leg [law]

legal (related to the law)

legislature (persons who make laws)

log, ology [word, study]

psychology (mind study)

zoology (animal study)

luc, lum [light]

lumen (a unit of light)

translucent (letting light come through)

magn [great]

magnificent (great)

magnify (increase to a greater size)

man [hand]

manicure (to fix the hands)

manufacture (to make by hand)

mania [madness]

kleptomania (an abnormal tendency to steal)

maniac (a mad person)

mar [sea, pool]

marine (related to the sea)

marsh (a wet, grassy area)