RichThesaurus
insubstantial
vs
pencil-necked
insubstantial
adj
Lacking substance; not real or strong.
pencil-necked
adj
Insubstantial; weak.
Having a very thin neck.
How often have the words
insubstantial
and
pencil-necked
occurred in a corpus of books?
(source:
Google Ngram Viewer
)