unexpectedly
The likely word is unfailing.
Aloof
loveless / unloved, or lonely
The word is cohabitation.
There is no one-word substitute in English for "son-in-law."
The word you want is florist.
The adverb could be freely or voluntarily.
Sportsmanship is a word substitute for spirit of game
The word metalworking is one word.
eat, use
The word that works is idiot.
what word can I substitute for constitutes