The Collaborative International Dictionary
Peninsulating
Peninsulate \Pen*in"su*late\, v. t. [imp. & p. p. Peninsulated; p. pr. & vb. n. Peninsulating.] To form into a peninsul
South River . . . peninsulates Castle Hill farm.
--W. Bentley.
Wiktionary
peninsulating
vb. (present participle of peninsulate English)