(archery) One who encouraged an archer by crying "Aim!" when he was about to shoot. / An encourager generally.

(obsolete) To encourage an archer when shooting by crying "aim". / (obsolete, by extension) To applaud or encourage.

(intransitive) To position oneself and/or one's weapon so as to be aimed specifically at a chosen mark or target (which is indicated after 'at') / (idiomatic) To direct criticism (towards).

Synonym of reach for the sky

A sequence of commands used to order soldiers to carefully fire their weapons

Used as a reminder that prompt action is often better than thoroughly planned action, especially in business. / Used to emphasize the dangers of acting hastily.