think over is a verb meaning "reflect deeply on a subject". It carries one recorded sense.
reflect deeply on a subject
“I mulled over the events of the afternoon”
“philosophers have speculated on the question of God for thousands of years”
“The scientist must stop to observe and start to excogitate”
Definitions, synonyms and semantic relations for think over come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.