What is "trembly"

Usage examples of "trembly".

Tottery, white-haired, half senile, the mage had gone down the line of horseboys and come back twice before stopping in front of Gawaine and leveling a trembly, liver-spotted hand at his nose.

I have that tired feeling you get after you've been swimming, my knees are all trembly and I'm a little hungry but mostly I'm just tired.