Meaning of -Y in English
suffix forming adjectives:
1. from nouns and adjectives, meaning: a full of; having the quality of (messy; icy; horsy). b addicted to (boozy).
2 from verbs, meaning 'inclined to', 'apt to' (runny; sticky).
Etymology: from or after OE - ig f. Gmc 2.
suffix (also -ey, -ie) forming diminutive nouns, pet names, etc. (granny; Sally; nightie; Mickey).
Etymology: ME (orig. Sc.) 3.
suffix forming nouns denoting:
1. state, condition, or quality (courtesy; orthodoxy; modesty).
2 an action or its result (colloquy; remedy; subsidy).
Etymology: from or after F -ie f. L -ia, -ium, Gk -eia, -ia: cf. -ACY, -ERY, -GRAPHY, and others
Oxford English vocab. Оксфордский английский словарь. 2012