One possible answer might be people - people get shorter the older they get.
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.
A candle. As it burns, it gets shorter in length but longer in wax height.
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.
Born then grows up then gets older and older then dies after old age or other other things like hit by a car.
night grows longer
Everything grows older (all physical things).
A candle.
They shed all their life. The period between shedding grows longer as the snake gets older.