The second element is a loan from Norse vaðil(l) "ford" which was borrowed as Gaelic fadhail (genitive fadhla). Through the process of reverse lenition fadhla, with the ethnonymic suffix -ach has led to the formation of Badhlach "a person from Benbecula".
Other interpretations that have been suggested over the years are Beinn Bheag a' bhFaodhla, supposedly meaning the "little mountain of the ford" and Beinn a' Bhuachaille, meaning "the herdsman's mountain".
The island is also known in Gaelic poetry as An t-Eilean Dorcha "the dark island".
The island lies between the islands of North Uist and South Uist, to which it is connected by road causeways. Travel to any of the other main Hebridean islands, or to the Scottish mainland, must be done by air or sea. Benbecula Airport on the island has daily flights to Glasgow, Stornoway and Barra. A direct service to Inverness was introduced in 2006 but discontinued in May 2007. There are no direct ferry services from Benbecula to the mainland, but a service operated by Caledonian MacBrayne from Lochboisdale on South Uist provides a five-hour crossing to Oban on the mainland, whilst another service from Lochmaddy on North Uist provides a two-hour crossing to Uig on the Inner Hebridean island of Skye, and hence to the mainland via the Skye Bridge. Ferry services from the islands of Berneray (linked by causeway to North Uist) and Eriskay (linked to South Uist) connect to the other Outer Hebridean islands of Harris and Barra respectively.
Benbecula's main settlement is Balivanich (Scottish Gaelic: Baile a' Mhanaich, meaning "Town of the Monk") in the northwest. It is the main administrative centre for the three islands, and has the council offices and the administrative centre for the artillery deep sea firing range on South Uist, which is managed by QinetiQ. The village is also home to the airport and the island's bank.
Other villages include Craigstrome, which lies on the eastern half of Benbecula. In contrast to the cultivated west coast of the island, the eastern half is a mixture of freshwater lochs, moorland, bog and deeply indenting sea lochs. Craigstrome is near Ruabhal, Benbecula's highest hill at 124 metres (407ft).
The township of Lionacleit is also an important one, housing the Uists' main secondary school, which also doubles as a community centre containing a swimming pool, cafeteria, sports facilities, a small museum and a library. Next door to this is the Lionacleit campus of Lews Castle College. Lionacleit lies on the main weat coastal road, approximately 1 mile from its junction with the north-south spinal road at Creagorry.
Creagorry is located at the south of the island, near to the causeway to South Uist. The Scottish Coop here is the main supermarket for the south of the island and for the north of South Uist.
The RAF radar station RRH Benbecula monitors the northern Atlantic.
In comparison, it remains a relatively strong Gaelic speaking area in spite of a continued decline. in the 2001 census, Benbecula overall had 56% Gaelic speakers. The weakest Gaelic speaking area is Balivanich with only 37%. All other areas on Benbecula range between 74% (Liniclete) and 62% (Gramsdale and Uachdar).