old soldier

Definitions

1. A former soldier, or one who has served for a long time.
   also, figuratively
2. Someone with a lot of experience in something; an old hand.
3. The butt of a smoked cigar, or an empty bottle of liquor.
   US, slang
4. A bottle whose contents are drunk at a single sitting.
   slang

Equivalents

Examples

“For almost 90 years, the dependable 350hp diesel-electrics and their predecessors have⟳ given loyal service to Britain's industrial and main line railways, but even these old soldiers can't go on forever.”

CEFR level