I don't think there is an answer to your question. The word itself brings about images of youth. But this may be of interest to you anyway:
Betjeman's language is, in its own peculiar way, quite obscure. This is especially true for 21st century readers, for whom the poems are full of unknown terms - words and references that have a very English music but don't make immediate sense. Try to get your head around these lines from Myfanwy:
"Kind o'er the kinderbank leans my Myfanwy"
"Home and Colonial, Star, International"
"Then what sardines in half-lighted passages!"
Betjeman wasn't so plain-talking a poet - he was a poet of the strange, gilded surfaces of a fast-vanishing moment, and his language was proportionally strange and gilded. Some of the specific meanings have vanished, but the effect of their music has not.