Longing, n.
An eager desire; a craving; a morbid appetite; an earnest wish; an aspiration. Put on my crown; I have immortal longings in me. Shak.
Shades of meaning
Fernald has no entry of its own for longing; he lists it under appetite, desire, eager.
Where he writes about it:
Longing is a reaching out with deep and persistent demand for that which is viewed as now distant but at some time attainable; as, the captive's longing for release. — from desire
Synonyms
appetitedesireeageranimatedanxiousappetencyardentaspirationburningconcupiscencecovetingcravingdesirousdispositionearnestenthusiasticferventglowinghankeringhotimpatientimpetuousimportunateimpulseinclinationintenseintentkeenlikinglustpassionproclivitypronenesspropensityrelishthirstvehementwishyearningzealouszest