Etymology From Middle English -ly, -li, -lik, -lich, -like, from Old English -līċ, from Proto-West Germanic *-līk, from Proto-Germanic *-līkaz (“having the body or form of”), from *līką (“body”) (whence lich). In form, probably influenced by Old Norse -ligr (“-ly”) (Norwegian Bokmål -lig, Faroese -ligur, Icelandic -legur). Cognate with Dutch -lijk, German -lich, Danish -lig and Swedish -lig. Doublet of -like, more at like.
1
Morpheme Used to form adjectives from nouns, the adjectives having the sense of "behaving like, or having a nature typical of what is denoted by the noun" Similar in meaning to -like but most often paired with animate nouns.
man + -ly → manly
comrade + -ly → comradely
2
Morpheme Used to form adjectives from nouns, the adjectives having the sense of "appearing like, resembling, or having the likeness of what is denoted by the noun".
bloom + -ly → bloomly
muscle + -ly → muscly
3
Morpheme Used to form adjectives from nouns specifying time intervals, the adjectives having the sense of "occurring at such intervals".