| a suffix, occurring in adjectives of Greek and Latin origin, meaning “pertaining to,” and (in nouns thence derived) also imitated in English (coffin; cousin, etc.). |

| a noun suffix used in a special manner in chemical and mineralogical nomenclature (glycerin; acetin, etc.). In spelling, usage wavers between -in and -ine. In chemistry a certain distinction of use is attempted, basic substances having the termination -ine rather than -in (aconitine; aniline, etc.), and -in being restricted to certain neutral compounds, glycerides, glucosides, and proteids (albumin; palmitin, etc.), but this distinction is not always observed. |
| a suffixal use of the adverb in, extracted from sit-in, forming compound nouns, usually from verbs, referring to organized protests through or in support of the named activity (kneel-in; chain-in; be-in) or, more generally, to any organized social or cultural activity (cook-in; sing-in). |
| -in suff.
[Variant of -ine2.] |
| -ine 2 suff.
[Ultimately from Latin -īnus and -inus, adj. suffixes; see -ine1.] |
-in suff.
Neutral chemical compound: inulin.
Pharmaceutical: rifampin.
Antibiotic: penicillin.
Antigen: tuberculin.
Variant of -ine2.