nymphet

• nymphette

From nymph +‎ -et (“diminutive”), first attested 1612. The second sense was popularized by Vladimir Nabokov's 1955 novel Lolita.

nymphet (plural nymphets)

1. (obsolete) A small nymph. [17th–19th c.]
   • 1612 Michael Drayton, Poly-Olbion I. xi. Argt. 171:

     Of the nymphets sporting there In Wyrrall, and in Delamere.

2. A sexually attractive girl or young woman. [from 20th c.]
   • 1955, Vladimir Nabokov, Lolita, 1st American edition, New York, N.Y.: G[eorge] P[almer] Putnam’s Sons, published August 1958, →OCLC, part 1, page 19:

     […] the fey grace, the elusive, shifty, soul-shattering, insidious charm that separates the nymphet from such coevals of hers […]

More common than the alternative spelling nymphette, which uses the more standard feminine suffix -ette.

• jailbait, lolita, nymph

• The changing English language, Brian Foster, 1968, pp. 185–186 – on spelling nymphet versus nymphette