What is the meaning of At-?

Prefix meaning at, close to, to, away, off.

romanization of 𐌰𐍄-

Usually found on verbs (and their derived nouns or adjectives) with the meaning 'away,' or also 'open' (like Russian от- (ot-)).

prefix indicating movement towards something (esp. speaker)

indicates the result of an action

off, away

re-

Prefix meaning away; toward; to

Prefix meaning at; against

Emphatic prefix meaning intensely or excessively

semi-reflexive prefix

alternative form of ant-

at, toward

with

allomorph of öt- (detransitivizing prefix)

again, back, re-

affirmative prefix, emphasises prefixed word

Source: wiktionary.org