The Collaborative International Dictionary
Coextending
Coextend \Co`ex*tend\, v. t. [imp. & p. p. Coextended; p. pr. & vb. n. Coextending.] To extend through the same space or time with another; to extend to the same degree.
According to which the least body may be coextended
with the greatest.
--Boyle.
Has your English language one single word that is
coextended through all these significations?
--Bentley.
Wiktionary
coextending
vb. (present participle of coextend English)