designating

"He is a student of life."

"The student council chose a representative to speak at the school assembly. "

"My daughter's teacher is very kind and helpful. "

"to designate the boundaries of a country"

"My younger sister is very good at distinguishing different types of flowers. "

"The fence clearly marks the boundaries between our yard and our neighbor's yard. "

"The teacher's description of the new math concept helped the students understand it better. "

"Her distinctive laugh, a high-pitched giggle, could be heard across the entire playground. "

"The specific of her success was her dedication to studying. "

"My purpose for studying hard is to get good grades in school. "

"The country surrounding our small village is mostly farmland. "

"The guard blew his whistle to indicate imminent departure."