Two distinct words share this spelling. The noun boon (benefit) comes from Old Norse bón ('prayer, petition, request'), related to Old English bēn ('entreaty'). The original sense was 'a favour asked for'; by the 16th century it had shifted to 'the favour or benefit granted', then to any timely blessing. The adjective boon (as in 'boon companion') comes from Old French bon ('good'), from Latin bonus.
What does boon mean?
As a noun, boon means a welcome benefit, blessing, or advantage — especially a timely or unexpected one: 'the new bus route was a boon for commuters'. As an archaic adjective, it means convivial or jolly, and survives mainly in the phrase 'boon companion'.
What is a 'boon companion'?
A boon companion is a close, jolly, and congenial friend — someone you enjoy spending time with. The phrase comes from Old French bon (good). It is old-fashioned but still appears in literary and formal contexts.
What is the opposite of boon?
The antonym of boon is bane — a cause of distress, harm, or misery. The pairing 'boon and bane' is a common literary device: something that is both a blessing and a curse.
Is boon a verb?
No. Boon is only a noun or (archaically) an adjective. There is no verb 'to boon'. If you mean to give a benefit, say 'this change benefits...' or 'this is a boon to...'
Where does the word boon come from?
The noun boon (benefit) comes from Old Norse bón, meaning a prayer or petition, related to Old English bēn (entreaty). The sense evolved from 'a favour asked for' to 'the favour granted' to any timely blessing. The unrelated adjective boon (boon companion) comes from Old French bon (good).