treillage vs espalier

treillage and espalier both are nouns.

Word	Noun	Adjective	Verb	Adverb
treillage	Yes	No	No	No
espalier	Yes	No	No	No

As nouns, espalier is a hyponym of treillage; that is, espalier is a word with a more specific, narrower meaning than treillage:

treillage: latticework used to support climbing plants
espalier: a trellis on which ornamental shrub or fruit tree is trained to grow flat

treillage (noun)	espalier (noun)
latticework used to support climbing plants	a trellis on which ornamental shrub or fruit tree is trained to grow flat