One possible answer might be people - people get shorter the older they get.
Life gets shorter, the longer it grows.
A panda bear's tail does not shorten as it gets older. However, the fur thickens around it and the bear grows much larger than its birth size, so it may appear shorter.
it gets smaller as it grows older
the older the watch gets the moire it grows in value
It erodes, and becomes smoother, rounder, and shorter. Like people do.
Both, but in my expeirience, women tend to do so more often.
night grows longer
Born then grows up then gets older and older then dies after old age or other other things like hit by a car.
Everything grows older (all physical things).
They shed all their life. The period between shedding grows longer as the snake gets older.
The answer is a candle because it is tall when it is new or 'young.' But as it gets used or 'older', it gets shorter because the wax melts.