Why does 縱 mean both "loose; vertical; although; even if"

Question

	詞類	英文意義
1	v.	loose; allow; relax; let go; let fly; be indulgent; release; set free
2	adj.	vertical; perpendicular; longitudinal; lengthwise
3	conj.	although
4	idiom	even if; granted that

http://humanum.arts.cuhk.edu.hk/Lexis/lexi-mf/search.php?word=%E7%B8%B1 wrote that "可能由於絲織品是由直線和橫線編織而成，故「縱」後來表示「直」，與「橫」相對。" Here's my translation in English — perhaps because silk fabrics are woven from straight and horizontal threads, 「縱」means straight, as opposed to "horizontal".

3. But the website did not elaborate 3 and 4? How is "although" related to "本義是一種絲織品。"?

4. How is "even if; granted that" related to "本義是一種絲織品。"?

Answer 1

『說文解字』- "(縱)緩也。一曰捨也。各本作舍也，由俗以舍捨通用也。今正。捨者，釋也。从糸從聲。足用切。九部。後人以爲從衡(橫)字者，非也。"

As indicated above, 縱 means "although", since it implies the relation of one "yield to" another, which is similar to the original meaning - "relax/release and soften"; as well as the idioms derived from it "縱使(even if),縱令(even though)".

『說文解字』disputes the origin of the word has something to do with 衡(transverse, horizontal, also 橫), for which, 豎 (vertical) is clearly the counterpart of it. This dispute puts the association of the origin of 縱 with the orientation of the threads in the (silk) fabrics in doubt, if not completely brushed aside. From this, your questions could well be based on a potentially "false" claim that bears no answer.

Answer 2

「縱」後來表示「直」，與「橫」相對

縱 -- a vertical line extends forward

橫 - a horizontal line extends sideways

縱 (extends forward) --> let go --> allow --> indulge

縱: although; even if; granted that

(allow one factor doesn't make other factors in a situation reasonable/ inevitable)

Example:

縱死不懼 - not afraid even if/ although facing death

you allow (accept) the fact that you are facing death, but it still doesn't make fear inevitable