English 'been' from PIE *bʰuH- (to grow, to become) is the third unrelated root in the 'to be' paradigm, and its original sense of growth and becoming connects it to 'build' (make something become), 'booth' (a dwelling), and 'husband' (house-dweller).
Past participle of 'be.'
From Old English 'beon' (to be, to become, to happen), from Proto-Germanic *beuną (to be, to become), from PIE *bʰuH- (to grow, to become, to come into being). This is the THIRD root in the 'to be' paradigm — distinct from *h₁es- (am/is) and *h₂wes- (was/were). The original meaning was 'to grow' or 'to become' — the German cognate 'bauen' means 'to build,' revealing that 'been' originally
'Been,' 'build,' 'booth,' and 'husband' all come from PIE *bʰuH- (to grow, to become). 'Build' is 'to make something become.' 'Booth' is 'a thing that has become' (a dwelling). 'Husband' is Old Norse 'húsbóndi' — 'house-dweller' (hús + bóndi, from búa, to dwell, from *bʰuH-). Even 'bondage' descends from this root