The Collaborative International Dictionary
Holloing
Hollo \Hol"lo\, v. i. [imp. & p. p. Holloed; p. pr. & vb. n. Holloing.] [See Hollo, interj., and cf. Halloo.] To call out or exclaim; to halloo.
Wiktionary
holloing
vb. (present participle of hollo English)