-ilis

From Proto-Italic *-elis, from Proto-Indo-European *-elis, probably from *-lós. Cognate with Proto-Germanic *-ilaz (“-le”, adjective-forming suffix).

• (Classical) IPA^(key): /i.lis/, [ɪlʲɪs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /i.lis/, [ilis] (stressed on the antepenult)

-ilis (neuter -ile, comparative -ilior, superlative -illimus or -ilissimus); third-declension two-termination suffix

1. -ile; used to form an adjective noun of relation, frequently passive, to the verb or root.

   ‎agō (“to act”) + ‎-ilis → ‎agilis (“that may be acted”)

   ‎frangō (“to break”) + ‎-ilis → ‎fragilis (“that may be broken”)

2. and sometimes to the perf. pass. part. stem:

   ‎sedeō (“to sit”) + ‎-ilis → ‎sessilis (“of sitting”)

   ‎pendeō (“to hang”) + ‎-ilis → ‎pensilis (“hanging”)

   ‎flectō (“to ply”) + ‎-ilis → ‎flexilis (“pliable”)

Third-declension two-termination adjective.

• -ānus, -āris, -icus, -ulus

• -ālis
• -ēlis
• -īlis
• -ūlis

Originally from the above -ilis added to i stems, later used freely (especially on r stems).

• (Classical) IPA^(key): /ˈiː.lis/, [ˈiːlʲɪs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /ˈi.lis/, [ˈiːlis]

-īlis (neuter -īle); third-declension two-termination suffix

1. -ile; used to form an adjective noun, usually from a noun, indicating a relationship or a pertaining to.

   ‎aedis (“building”) + ‎-ilis → ‎aedīlis (“of buildings”) (attested as substantive)

   ‎hostis (“enemy”) + ‎-ilis → ‎hostīlis (“of the enemy, unfriendly, hostile”)

   ‎puer (“boy”) + ‎-ilis → ‎puerīlis (“of boys, boyish, immature”)

   ‎erus (“master”) + ‎-ilis → ‎erīlis (“of the master”)

Third-declension two-termination adjective.

• -bilis