Definition of pipping:
(n) :
Any of various respiratory diseases in birds, especially infectious coryza.
(n) :
(humorous, dated) Of humans, a disease, malaise or depression.
(n) :
(UK) A seed inside certain fleshy fruits, such as the stone (pit) of a stonefruit or the smaller seeds of an orange or apple.
(n) :
(US, colloquial) Something or someone excellent, of high quality.
(n) :
(British, dated, World War I, signalese) P in RAF phonetic alphabet.
(v) :
(transitive) To remove the pips from.