Etymology
1. From Middle English tall, talle, tal (“seemly, becoming, handsome, good-looking, excellent, good, valiant, lively in speech, bold, great, large, big”), from Old English *tæl, ġetæl (“swift, ready, having mastery of”), from Proto-Germanic *talaz (“submissive, pliable, obedient”), from Proto-Indo-European *dol-, *del- (“to aim, calculate, adjust, reckon”).
2. Cognate with Scots tal (“high, lofty, tall”), Old Frisian tel (“swift”), Old Saxon gital (“quick”), Old High German gizal (“active, agile”), Gothic 𐌿𐌽𐍄𐌰𐌻𐍃 (untals, “indocile, disobedient”).
3. The Oxford English Dictionary notes: "The sense development [of tall] is remarkable, but is paralleled more or less by that of other adjectives expressing estimation, such as buxom, canny, clean, clever, cunning, deft, elegant, handsome, pretty, proper; German klein, as compared with English clean, presents the antithesis to modern tall as compared to tall in early Middle English. It has been conjectured that in the sense 'high of stature' it is a different word, adopted from the Welsh tal in some sense; but the latter is, according to Professor Rhŷs, merely a 16th-century borrowing of the English word (in Owen Pughe's Dictionary erroneously mixed up with the genuine Welsh word tal (“end, brow, forehead”), with which it has no possible connection.)" See: Gothic Adjectives '
𐌿𐌽𐍄𐌰𐌻𐍃'.