PENINSULATE

Etymology

Verb

peninsulate (third-person singular simple present peninsulates, present participle peninsulating, simple past and past participle peninsulated)

(transitive) To make into a peninsula; to surround almost entirely with water.

Source: Wiktionary

Pen*in"su*late, v. t. [imp. & p. p. Peninsulated; p. pr. & vb. n. Peninsulating.]

Definition: To form into a peninsula. South River . . . peninsulates Castle Hill farm. W. Bentley.

Source: Webster’s Unabridged Dictionary 1913 Edition