sink in is a verb meaning "become clear or enter one's consciousness or emotions". It carries 2 recorded senses.
become clear or enter one's consciousness or emotions
“It dawned on him that she had betrayed him”
“she was penetrated with sorrow”
pass through
“Water permeates sand easily”
Definitions, synonyms and semantic relations for sink in come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.