1 to raise

2 to increase

1 newly added

2 additional

3 to add (to what already exists)

1 (two, three etc) -fold

2 times (multiplier)

3 double

4 to increase or multiply

1 to feel even more

2 to be extremely (sad, lonely, delighted etc)

1 to double

2 to redouble

1 half the work, twice the effect (idiom); the right approach saves effort and leads to better results

2 a stitch in time saves nine

1 brimming with confidence (idiom)

1 constantly increasing without limit (idiom); rapid progress in all directions

1 to increase without letup

2 to get worse and worse (idiom)

1 lit. vitality a hundredfold (idiom); refreshed

2 one's vigor thoroughly restored