mend

v.

1. To repair

   repair, patch, patch up, darn, sew, fix, restore, reconstruct, retouch, put in shape, heal, put back together, cobble, doctor*; see also reconstruct, repair, restore 3.

2. To improve

   aid, remedy, cure; see correct 1, improve 1.

3. Reform

   regenerate, behave, mend one's manners, mend one's ways; see improve 2, reform 3.

4. To get well

   recover, respond to medication, knit; see heal 1, recover 3.

mend is the general word implying the making whole again of something that has been broken, torn, etc. to mend a toy, to mend a dress; repair, often equivalent to mend, is preferred when the object is a relatively complex one that has become damaged or decayed through use, age, exhaustion, etc. to repair an automobile, to repair a radio; patch and darn imply the mending of a hole, tear, etc., the former by inserting or applying a piece of similar material to patch a coat, to patch a tire, the latter by sewing a network of stitches across the gap to darn a sock

on the mend