1a) of a branch of a tree that is full of sap
Part of Speech: adjective
Of uncertain derivation; soft: - tender.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root ἁπαλός; click on the second column to search for that grammatical form of the root ἁπαλός; click on the third column to search for that word and grammatical form; click on the total to search for the root ἁπαλός.