Also see Frenulectomy
1) Penis: a short frenulum of the penis restricts normal retraction of the foreskin during erection (a condition known as frenulum breve). This may be a complication of circumcision or a naturally occurring event. The goal of treatment is to allow normal retraction of the foreskin. Circumcision may relieve this condition but is not indicated solely for treating frenulum breve.
2) Tongue: A tight frenulum in this context is sometimes referred to as "tongue-tie" which is also known as ankyloglossia. In this condition the frenulum of the tongue restricts range of motion which may interfere with breastfeeding or speech. A less extensive clipping of the lingual frenulum is known as a frenotomy (see this WebMD Link). An illustration of this procedure can be found here.
The term frenulum (pl. frena), refers to any fold in a mucous membrane that secures or restricts movement of two mobile tissues with respect to each other. Other examples of frena in the mouth include the buccal frena (connect cheeks to gum) and the labial frena (connects lips to gum).
A frenulectomy is generally considered a minor procedure, and may be performed under local anaesthetic or general anesthesia if the resection is more extensive or if the patient is too young to cooperate as needed to perform the procedure.
If the repair is extensive, it may require closure with absorbable sutures, which fall out in approximately 10 days - and the patient is usually put on a short course of analgesics to deal with the short lived discomfort.