These definitions of motivation and emotion were developed by participants in Motivation and Emotion (2010-2011, 2013). Feel free to add your definitions:

Motivation

1. Motivation is a process towards a goal; it provides an individual with energy and direction.
2. Motivation is internal or external drive to achieve something.
3. A force that drives behaviour and gives it direction towards satisfying a need or desire.
4. Process that drive behaviour.
5. Energy or drive that results in behaviour.
6. The reason as to why you do or don't engage in a particular behaviour, taking energy and directing it towards a goal.
7. An energy that drives somone towards or away from something, conscious or unconscious, to return the body to a state of homeostasis (equilibrium).
8. The psychological and/or physiological impulses which provide a desire/cause to behave and think; drive to do something.
9. The urge to act with purposeful intent.
10. The internal drive to achieve a goal.
11. Inclinations towards or away from specific behaviours.
12. An internal force that directs an organism to a particular internal or external behaviour and the intensity of application to that end.
13. A need or a want that drives a behaviour towards an internal or external goal.
14. An innate tendency towards a certain behaviour provoked by an internal or external stimuli.
15. Internal or external drives that energises an individual's behaviour.
16. The drive to do something.
17. A desire or willingness to do something.
18. Internal or external reasons for doing something or not doing something.
19. A directed energy to do something that can vary in strengths and priority - something you want, need, or desire and it can be internal or external.
20. A need, cognition, function or emotion that drives organisms to engage and continue with and terminate behaviour.
21. An internal or external driving force behind a person's actions and behaviour.
22. A drive which can be internal or external which compels us to perform certain behaviours which includes energy and direction.
23. The driving force behind any behaviour.
24. The drive for energy and direction utilised in setting a goal or goal-setting behaviour.
25. The drive and energy that urges/pushes an individual towards a particular goal through behaviour.
26. Gives energy to direct behaviour.
27. Processes that give behaviour direction and energy.
28. Energy and direction to behave in a goal-directed way.
29. Energy to direct or focus on a task, eliciting a behaviour.
30. Our internal individual drive that influences our behaviour, needs and desire to set goals.
31. An internal drive which directs action.
32. Internal drive or knowledge that pushes an individual to perform an action.

Emotion

1. Internal state influencing the way we feel at any given moment.
2. A feeling that affects the overall mood of an individual both physically and mentally.
3. The expression of a feeling or state of mind.
4. A chemical reaction we experience in a physiological and psychological way.
5. Internal voice that can influence motivation and behaviour.
6. A temporary internal state or reaction to an event.
7. A physiological state of being.
8. The psychological state.
9. Something that follows our thoughts and guides our moods and behaviour.
10. Internal sensation or state of mind.
11. Temporary feeling-based responses to ongoing events.
12. A strong feeling or sensation based on internal or external forces.
13. A rational or irrational feeling that manifests from thoughts and cognitions and fluctates throughout the day in intensity.
14. An internal combination of physiological and cognitive states in response to a thought or an event.
15. An individual's response to internal or external stimulu that maybe temporary or subjective and can influence our physiological state or behaviour.
16. How you feel about a situation or event.
17. The state of mind drawing upon circumstances, experiences etc.
18. Passing sense of affect in response to an internal or external circumstance or state.
19. A state of mind, thoughts affecting feelings, extrinsic forces in varying strengths and physiological reactions.
20. A short-term, subjective-physiological-functional-expressive phenomenon.
21. A concept to describe a physiological state at any given point in time.
22. A psychological state of mind.
23. A state of mind which is determined by thoughts and feelings.
24. A fuzzy construct that its difficult to pin down, subjective in nature, can be a physiological state and psychological moment.
25. The feelings an individual experiences in response to cognitions, thoughts, physiological influences and external stimuli.
26. Feelings that affect a person's behaviour; emotions are intense and short.
27. Cognitive thoughts and feelings that are descriptive in nature.
28. Psychological and physiological state that influences thoughts, feelings and behaviours.
29. The chemical reactions within our bodies that are reflected through our behaviours and feelings.
30. A personal disposition towards, and subjective interpretation of past, present and future life events.
31. A short-lived psychological state and expression of internal feelings.
32. Feelings, energy, unconscious reactions to internal and external stimuli.