Reconstruction:Proto-Germanic/swalwǭ

Etymology
. Possibly related to. Possibly related to 🇨🇬, in which case the corresponding PGmc reconstruction would be.

Kroonen compares and, explaining that the gannet and swallow were named for their wedge-shaped tails. In this case, the original form would have developed into  by.

Noun

 * 1)  swallow (bird)