Not unless it is at the start of a sentence or part of a formal name as in Ukulele Ike.
Strings
The ukulele was originally developed in Hawaii, which was a country at the time. Now it is part of the US. It was based on an instrument from the Portuguese islands of Madeira.
It would be a noun normally, but could be used as an adjective. He played the ukulele. Noun He picked up some ukulele music. Adjective.
esophagus
A funnel with a long stem (the straight part below the cone shaped part)
The bridge is the structure on the face of the ukulele that the strings are attached to. The other end of the strings is attached to the tuners on the head.
Straight of Dover
No, the ukulele is a string instrument. It is a member of the lute family. Some people do 'hit' the body to get a percussion sound to keep time.
A funnel with a long stem (the straight part below the cone shaped part)
Curves with hills, especially after a long straight part of the highway.
the barrel is the long part that the bulliet comes out