declare oneself is a verb meaning "ask (someone) to marry you". It carries one recorded sense.
ask (someone) to marry you
“he popped the question on Sunday night”
“she proposed marriage to the man she had known for only two months”
“The old bachelor finally declared himself to the young woman”
Definitions, synonyms and semantic relations for declare oneself come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.