tunnel

Forms

1.An underground or underwater passage.
- In 1865 an outfit called the East London Railway Company bought the Brunel tunnel for £800,000, and in 1869 they opened a railway through it.
2.A passage through or under some obstacle.
- There are more than 1,500 railway tunnels in Britain and the majority are still in use, carrying working tracks beneath Britain's most inconvenient geographic features.
- But very soon he grew to like it, for the Boy used to talk to him, and made nice tunnels for him under the bedclothes that he said were like the burrows the real rabbits lived in.
3.A hole in the ground made by an animal, a burrow.
4.A wrapper for a protocol that cannot otherwise be used because it is unsupported, blocked, or insecure.

1.To insert a catheter into a vein to allow long-term use.
2.To make a tunnel through or under something; to burrow.
- The 1955 Act gave powers for compulsory acquisition of "easements", or permission to tunnel beneath dwelling houses instead of, as had previously been necessary, following approximately the course of surface roads.
3.To dig a tunnel.
4.To transmit something through a tunnel (wrapper for an insecure or unsupported protocol).

Uncommon· #3600

From Middle French tonnelle (“net”) or tonel (“cask”), diminutive of Old French tonne (“cask”), a word of uncertain origin and affiliation.

Related to Old English tunne (“tun; cask; barrel”).

More at tun.