A strip, especially one around the edge of something (for example, in some old heraldry).
… round about a border of Purple Veluet, with Floure de luces of Gold, embrodred to the full, with a welt and bordure of Ermines foure fingers broad. / Vpon the last named cloath or Couerlet of St / …
1688, Randle Holme, The academy of armory, book 1, chapter IV, "Of the Bend divers ways":
Therefore this may be taken for an Observation, that an edg, or hem, or welt, only runs on the sides of the Ordinary; but the Border invirons, or goeth clear round the same, […]
(obsolete, shoemaking) A shoe made with a welt (strip of leather set into the seam).
verb
To cause to have welts; to beat.
To install welt (a welt or welts) to reinforce.
verb
(UK, dialect, archaic, intransitive) To decay.
(UK, dialect, archaic, intransitive) To become stringy.