Middle English word bouk comes from Proto-Indo-European *bū-, Proto-Indo-European *bʰuǵ- (Buck, he-goat.), Proto-Indo-European *bʰugo-, Proto-Indo-European *bʰōw-, Proto-Indo-European *bhug̑-
| Dictionary entry | Language | Definition |
|---|---|---|
| *bū- | Proto-Indo-European (ine-pro) | |
| *bʰuǵ- | Proto-Indo-European (ine-pro) | Buck, he-goat. |
| *bʰugo- | Proto-Indo-European (ine-pro) | |
| *bʰōw- | Proto-Indo-European (ine-pro) | to swell, inflate, to blow, swell , to dwell |
| *bhug̑- | Proto-Indo-European (ine-pro) | |
| *būkaz | Proto-Germanic (gem-pro) | Belly, abdomen. Body. |
| būc | Old English (ang) | |
| *bukkô | Proto-Germanic (gem-pro) | |
| buc | Old English (ang) | Buck (male deer). |
| bouk | Middle English (enm) |