Perturb is a synonym of disturb, but, like most synonyms, the two terms are not exactly interchangeable. Disturb is the more common verb of the two, and it is often used to mean “to interrupt,” as in, Please don’t disturb me when I’m working, or, He kept the TV volume low because he didn’t want to disturb his wife’s nap. Perturb implies more agitation and sometimes annoyance or frustration. The careless actions or insensitive words of a person might perturb someone more attuned to their surroundings. Perturb has a distinct meaning in astronomy, where it means "to cause deviation of a celestial body from a regular orbit," as by the presence of one or more other bodies. This celestial disturbance is called perturbation.
When you treasure someone or something, you regard that person or thing as precious, the way you might regard literal treasure (you know, all those gold bars and jewels you have tucked in a giant chest somewhere). When you cherish someone, the affection and fondness is even greater. To cherish is to hold or treat as dear, or to feel love for. On this Mother's Day, many of us are taking time to express just how much we cherish our moms (though it's a tall order!). Cherish is also used to talk about clinging fondly to something, such as a special memory or a gift from a loved one: She cherished the summer she spent traveling with her kids and grandkids.
We admit: the English language is no picnic. In part because its words have so many meanings! For example, in the example we just gave, the verb admit means something close to “acknowledge” or even “confess.” But admit can also refer to allowing entry, as in the case of a college that admits a student, or to giving right of entrance, as in the case of a ticket that admits two people. The synonym concede is used more narrowly to talk about acknowledging claims or statements as true, just, or proper: He finally conceded that she was right. During an election, concede is used to talk about acknowledging an opponent’s victory before it is officially established or admitting defeat.