present or ready for immediate use or service
accessible or obtainable
present or free for consultation, etc; not otherwise occupied
The doctor is not available just now
present in such chemical or physical form as to be usable, e.g. by a plant
available nitrogen
availability /-ʹbiliti/ noun
availableness noun
availably adv
[Middle English in the senses ‘advantageous’, ‘beneficial’, from availen (see avail1) + -able]