Wiktionary
cowardy custard
n. (context childish English) A coward; a timid or fearful person.
Wikipedia
Cowardy Custard
Cowardy Custard is a musical revue and was one of the last Noël Coward shows staged during his life. It was devised by Gerard Frow, Alan Strachan and Wendy Toye. A book, also titled Cowardy Custard, was published in connection with the revue, similarly celebrating the Coward image.
The biographical revue premiered in London in 1972, running for 405 performances. A revised version toured in the UK in 2011.
The term "cowardy custard" is a taunt used by small children in the UK equivalent to "scaredy cat" in the US.
Usage examples of "cowardy custard".
So Icalled him a cowardy custard who didn't dare shut me upbecause everything I said was true.