Word Study
what is more
WORDNET DICTIONARY
Adverbial what is more has 1 sense
- what is more(r = adv.all) furthermore, moreover - in addition; "computer chess games are getting cheaper all the time; furthermore, their quality is improving"; "the cellar was dark; moreover, mice nested there"; "what is more, there's no sign of a change"
For further exploring for "what is more" in Webster Dictionary Online