Ennis Del Mar as many of us know means "Island of the Sea." Ennis" is Irish Gaelic for "island," “del Mar” Spanish, of the sea. It sums up the character of Ennis pretty well - Ennis's isolation and remoteness.
On the other hand, Twist, according to the dictionary, it means
1.
1. To wind together (two or more threads, for example) so as to produce a single strand.
2. To form in this manner: twist a length of rope from strands of hemp.
2. To wind or coil (vines or rope, for example) about something.
3. To interlock or interlace: twist flowers in one's hair.
4. To make (one's way) in a tortuous manner: twisted my way through the briar patch.
5. To turn so as to face another direction: twisted their heads around at the sound of the doorbell.
6. To impart a spiral or coiling shape to, as by turning the ends in opposite directions: twisting wire into a loop.
7.
1. To turn or open by turning: twisted off the bottle cap.
2. To pull, break, or snap by turning: twist off a dead branch.
8. To wrench or sprain: twist one's wrist.
9. To alter the normal aspect of; contort: twist one's mouth into a wry smile.
10. To alter or distort the intended meaning of: The cross-examiner twisted the words of the witness. See synonyms at distort.
11. To alter or distort the mental, moral, or emotional character of: The trauma twisted the child's outlook.
I came across this interview with Jake where he explained what "Twist" really means.
"Annie Proulx wrote me a note very recently that has made the entire movie—making it—totally worth it, no matter what happens, and how people respond to the film. She wrote me a note with a limited edition copy of Close Range, which is the book that “Brokeback Mountain” the short story is in. In it she said that Jack
“Twist” refers to the strength of the thighs and butt muscles that a bull rider has to have in order to stay on the bull. I had never really thought of it that way. It's so funny, it's so clearly in your face the whole time and you never really know what that is. I thought, “Yeah, there's a real endurance.”
http://www.aboutfilm.com/movies/b/brokebackmountain/gyllenhaal.htmI suppose we can extend that to the strength that Jack has to have to continue his relationship with Ennis.
BBM never ceases to amaze me its symbolism. It is simply brilliant.