Entries linking to encompass
Also used with native and imported elements to form verbs from nouns and adjectives, with a sense "put in or on" (encircle), also "cause to be, make into" (endear), and used as an intensive (enclose). Spelling variants in French that were brought over into Middle English account for parallels such as ensure/insure, and most en- words in English had at one time or another a variant in in-, and vice versa.
c. 1300, "space, area, extent, circumference," from Old French compas "circle, radius; size, extent; pair of compasses" (12c.), from compasser "to go around, measure (with a compass); divide equally," from Vulgar Latin *compassare "to pace out," from Latin com "with, together" (see com-) + passus "a step" (from PIE root *pete- "to spread").
The mathematical instrument for describing circles was so called in English from mid-14c. The mariners' directional tool (so called since early 15c.) took the name, perhaps, because it's round and has a point like the mathematical instrument.
Meaning "limits, boundary" is from 1550s. Sense of "range of notes which a given voice or instrument can produce" is from 1590s.
The word is in most European languages, with a mathematical sense in Romance, a nautical sense in Germanic, and both in English. In Middle English it also could mean "ingenuity, subtlety, cunning." Also an adverb in Middle English: to go compass was "go in a circle, go around."