LEAPFROGGING
Credit: GAMES Magazine - Mar. 1983
Ralph Maus

The right pair of letters will turn each three-letter string below into a seven-letter word, if you place that pair at both the beginning and end of each group.  For example, given the clue letters STO, the letter pair RE could be added at the beginning and end to form RESTORE.

1. YLI
2. ALG
3. RMI
4. GIB
5. GRA
6. LIV

HINTS:
The first letter of the letter pairs are:
1. S
2. A
3. T
4. L
5. D
6. E

Answers:

1. STYLIST
2. AMALGAM
3. TERMITE
4. LEGIBLE
5. DEGRADE
6. ENLIVEN