Boyd’s Bible Dictionary:
(bitter). A gum resin much prized and variously used (Ex. 30:23; Esther 2:12; Psa. 45:8; Prov. 7:17; Mark 15:23; John 19:39).
Concise Bible Dictionary:
Commiphora Myrrha
1. lot. This is judged to be a fragrant resinous gum gathered from the leaves of the cistus, or rock rose (Gen. 37:25; 43:11).
2. mor, Arabic murr. The true myrrh, so called because it distils its gum as tears, which harden into a bitter aromatic gum. It was an ingredient in the holy anointing oil, and was much prized as a perfume (Ex. 30:23; Esther 2:12; Psa. 45:8; Prov. 7:17; Song of Sol. 1:13; 3:6; 4:6,14; 5:1,5,1)3. It is identified with the balsamodendron myrrha and other allied species. In the New Testament the same is alluded to under the name of σμύρνα. The Magi presented myrrh with frankincense to the Lord at His birth, and it was used at His burial. Mingled with wine it was offered to Him as a stupefying drink before He was crucified, but He refused it (Matt. 2:11; Mark 15:23; John 19:39).