A lifeline

[Photo: The red yarn is a well used life line.]

frog

v.
to unravel a knitted garment. Also frog stitch v., to intentionally rip out a seam, and 
n., 
an intentionally ripped seam.

un·rav·el

v.
1. to separate or disentangle the threads of (a woven orknitted fabric, a rope, etc.)
2.to free from complication or difficulty; make plain or clear;solve: to
unravel a situation; to unravel a mystery.
3.Informal . to take apart; undo; destroy (a plan, agreement,or arrangement).
4.to become unraveled.

rav·el

 v.
1.to disentangle or unravel the threads or fibers of (a wovenor knitted fabric, rope, etc.).
2.to tangle or entangle.
3.to involve; confuse; perplex.
4.to make clear; unravel (often followed by out ).
5.to become disjoined thread by thread or fiber by fiber; fray.
6.to become tangled.
7.to become confused or perplexed.
8.(of a road surface) to lose aggregate.
Note to self: funny how there are three words used to describe ripping out (there's another one!) your knitting, and only one for knitting up.

frustration

 n.
1.the condition of being frustrated
2.something that frustrates
3. to become unraveled (okay I put this one in here, but it does fit).  See ravel, unravel and frog.

life-line

 n.
1.a. An anchored line thrown as a support to someone falling or drowning.
b. A line shot to a ship in distress.
c. A line used to raise and lower deep-sea divers.
2.a. A means or route by which necessary supplies are transported.
b. One that is or is regarded as a source of salvation in a crisis.
3.A diagonal line crossing the palm of the hand and believed to indicate the length and major events of one's life.
4.a length of smooth waste yarn which is inserted through the sts of a row or round of knitting using a darning needle, usually while working a complicated lace pattern. If you make an irreparable error and need to rip back, the lifeline provides an easy point to rip back to, and ensures that you will not lose any stitches.

re·lief

 n.
1.alleviation, ease, or deliverance through the removal of pain, distress, oppression, etc.
2.a means or thing that relieves pain, distress, anxiety, etc.
3.money, food, or other help given to those in poverty or need.
4.something affording a pleasing change, as from monotony.
5.release from a post of duty, as by the arrival of a substitute or replacement.
6. a feeling of relaxation after tenseness when you can take the life line out without having used it.  (okay, another one I added)