by the side of
• close to.
• "a house by the side of the road"
on the side
• in addition to one's regular job or as a subsidiary source of income.
• "no one lived in the property, but the caretaker made a little on the side by letting rooms out"
• secretly, especially with regard to a relationship in addition to one's legal or regular partner.
• "Brian had a mistress on the side"
• served separately from the main dish.
• "a club sandwich with French fries on the side"
