engaged in as a pastime; "an amateur painter"; "gained valuable experience in amateur theatricals"; "recreational golfers"; "reading matter that is both recreational and mentally stimulating"; "unpaid extras in the documentary"
serve as a teacher or trusted counselor; "The famous professor mentored him during his years in graduate school"; "She is a fine lecturer but she doesn't like mentoring"
tending to or capable of propelling; "propellant fuel for submarines"; "the faster a jet plane goes the greater its propulsive efficiency"; "universities...the seats of propulsive thought"