What was 'gall' that was given to Jesus at the crufixion?

Gall (1.) Heb. mererah , meaning "bitterness" (Job 16:13); i.e., the bile secreted in the liver. This word is also used of the poison of asps (Job 20:14), and of the vitals, the seat of life (Job 20:25). (2.) Heb. rosh . In Deu 32:33 and Job 20:16 it denotes the poison of serpents. In Hos 10:4 the Hebrew word is rendered "hemlock." The original probably denotes some bitter, poisonous plant, most probably the poppy, which grows up quickly, and is therefore coupled with wormwood (Deu 29:18; Jer 9:15; Lam 3:19). Compare Jer 8:14; Jer 23:15, "water of gall," Gesenius, "poppy juice;" others, "water of hemlock," "bitter water." Gr. chole (Mat 27:34), the LXX. translation of the Hebrew rosh in Psa 69:21, which foretells our Lord's sufferings. The drink offered to our Lord was vinegar (made of light wine rendered acid, the common drink of Roman soldiers) "mingled with gall," or, according to Mark (Mar 15:23), "mingled with myrrh;" both expressions meaning the same thing, namely, that the vinegar was made bitter by the infusion of wormwood or some other bitter substance, usually given, according to a merciful custom, as an anodyne to those who were crucified, to render them insensible to pain. Our Lord, knowing this, refuses to drink it. He would take nothing to cloud his faculties or blunt the pain of dying. He chooses to suffer every element of woe in the bitter cup of agony given him by the Father (Joh 18:11).