The Collaborative International Dictionary
Circumflexing
Circumflex \Cir"cum*flex\, v. t. [imp. & p. p. Circumflexed;
p. pr. & vb. n. Circumflexing.]
To mark or pronounce with a circumflex.
--Walker.
Wiktionary
circumflexing
vb. (present participle of circumflex English)