truncate

(verb) replace a corner by a plane.

(verb) approximate by ignoring all terms beyond a chosen one. Examples: "Truncate a series."

(verb) make shorter as if by cutting off. Synonyms: cut short. Examples: "Truncate a word." "Erosion has truncated the ridges of the mountains."

(adj) terminating abruptly by having or as if having an end or point cut off. Synonyms: truncated. Examples: "A truncate leaf." "Truncated volcanic mountains." "A truncated pyramid."