Origin and history of boundless

c. 1300, "boundary marker," from Anglo-Latin bunda, from Old French bonde "limit, boundary, boundary stone" (12c., Modern French borne), a variant of bodne, from Medieval Latin bodina, which is perhaps from Gaulish.

It is attested from mid-14c. as "an external limit, that which limits or circumscribes;" figuratively, of feelings, etc., from late 14c. From late 14c. as "limits of an estate or territory." Now chiefly in the phrase out of bounds, which originally referred to limits imposed on students at schools (by 1751); the other senses generally have gone with boundary.

word-forming element meaning "lacking, cannot be, does not," from Old English -leas, from leas "free (from), devoid (of), false, feigned," from Proto-Germanic *lausaz (cognates: Dutch -loos, German -los "-less," Old Norse lauss "loose, free, vacant, dissolute," Middle Dutch los, German los "loose, free," Gothic laus "empty, vain"), from PIE root *leu- "to loosen, divide, cut apart." Related to loose and lease.