Where does “ship of the line ensign second class” come from?

ship of the line ensign second class (English) comes from English ensign, from Middle English ensigne, from Old French enseigne, from Latin īnsignia.

ship of the line ensign second class (English): Most junior officer used in the navies of some Francophone countries, usually equal in rank to the British rank of midshipman or the American rank of ensign

Definitions

Most junior officer used in the navies of some Francophone countries, usually equal in rank to the British rank of midshipman or the American rank of ensign

Ancestry of “ship of the line ensign second class”, step by step

ship of the line ensign second class traces back through 3 separate lines of ancestry.

via English ensign

Step	Language	Word	Meaning
1	English	ensign	A badge of office, rank, or power; The lowest...
2	Middle English	ensigne	—
3	Old French	enseigne	—
4	Latin	īnsignia	—

via English ship of the line

Step	Language	Word	Meaning
1	English	ship of the line	A large square-rigged warship large enough to have a place in the line of battle, with up to 140 guns on at least two decks. A capital ship from the age of sail, superior to a frigate; usually, a seventy-four, or three-decker

via English second class

Step	Language	Word	Meaning
1	English	second class	The second-lowest rank in the Boy Scouts of America, between tenderfoot and first class

Every word from Latin īnsignia →Every word from Old French enseigne →Every word from Middle English ensigne →