(transitive) to open / (transitive) to begin, to initiate / (reflexive) to open (of a door or a flower) / (reflexive) to open, to begin

(transitive) to open completely

open the ball (to begin operations; to set things in motion)

(transitive with sur) (informal, figuratively) to wake up to (something), to wake up and smell the coffee / (transitive with à and with sur) (informal, figuratively) to open someone's eyes to (something)

(transitive with à) (figuratively) to pave the way for, to blaze the trail for

(literally, transitive with à) to open the door to someone / (figuratively, transitive with à) to open the door to something

(of a business or an organization) to open its doors for the first time, to open its doors to the public, to begin operating

(sports) to break the deadlock (to score the first goal in a match)

to lead the way

(figuratively) to open the ball (to begin operations; to set things in motion)