attachment vs connexion

attachment and connexion both are nouns.

Word	Noun	Adjective	Verb	Adverb
attachment	Yes	No	No	No
connexion	Yes	No	No	No

As nouns, connexion is a hypernym of attachment; that is, connexion is a word with a broader meaning than attachment:

attachment: the act of fastening things together
connexion: the act of bringing two things into contact (especially for communication)

Other hypernyms of attachment include connection, joining.

As nouns, connexion is a hypernym of attachment; that is, connexion is a word with a broader meaning than attachment:

Other hypernyms of attachment include connecter, connection, connective, connector.

attachment (noun)	connexion (noun)
the act of fastening things together	the act of bringing two things into contact (especially for communication)
the act of attaching or affixing something	shifting from one form of transportation to another
faithful support for a cause or political party or religion	an instrumentality that connects
a supplementary part or accessory	the process of bringing ideas or events together in memory or imagination
a connection that fastens things together	a relation between things or events (as in the case of one causing the other or sharing features with it)
a writ authorizing the seizure of property that may be needed for the payment of a judgment in a judicial proceeding	a connecting shape
a feeling of affection for a person or an institution