1 to count backwards (from 10 down to 0)

2 to count down

3 from the bottom (lines on a page)

4 from the back (rows of seats)

1 fickle

2 multi-variate (math.)

1 (great) majority

1 (numerical, statistical) index

2 (math.) exponent

3 index

4 exponential (function, growth)

1 to change

2 to alter

3 to transform

1 one scare after another (idiom)

2 in a constant state of tension

1 nothing much changes (idiom); always the same

2 stuck in a rut

1 lit. their number cannot be counted (idiom); fig. countless

2 innumerable

1 to show no understanding of the times (idiom); cannot adapt to current circumstances

2 not amenable to reason

1 unchanging since times immemorial (idiom)

2 unalterable

3 unvarying

4 monotonous