Another synonym is intermittent.
You could also use the words random irregular occasional
His aim was sporadic and the bullet holes were scattered randomly.
There is no one-word substitute in English for "son-in-law."
The word you want is florist.
Sportsmanship is a word substitute for spirit of game
The root word for "sporadic" is "sporad" which comes from the Late Latin word "sporadicus," meaning scattered or isolated.
The word metalworking is one word.
One possible substitute for "their" is "his" or "her" depending on the gender of the person/people being referred to. Another substitute can be "its" when referring to a non-human object or entity.
eat, use
The word that works is idiot.
Elevate
A walker is a pedestrian.
Traditionalist