Wiktionary
n. 1 (context military English) a military rank for a field officer above that of captain and below that of major 2 (context military English) a military rank for a naval officer above that of captain and below the admiral ranks or flag ranks
Wikipedia
Senior captain is a rare military rank which is used in some countries armed forces, navies and merchant marines.
Usage examples of "senior captain".
She had lost a topmast in the last blow, which slowed her down, but she had been well in sight at nightfall, and she had responded to Captain Griffiths's signal to chase: for Captain Griffiths was the senior captain.
The sub-majer can see a chandlery, a cooper's shop, a weaver's, perhaps a fuller's, before he reaches the senior captain.
The detail chief, he figured, was a medium-to-senior captain, and the rest of his troops j.
Owensford felt the regimental adjutant's fingers remove the Captain's pips from his shoulderboards, replace the five small company-grade stars of a senior captain with the single larger star of a major.
Yusuo's brother, Torajiro Sato, had flown F-86 fighters for the Air Self-Defense Force, then quit in disgust at the demeaning status of the air arm, and now flew as a senior captain for Japan Air Lines.
He didn't think that the senior captain would approve such goings-on.
Truman had been a captain of the list then, and once more she'd been Lady Harrington's second-in-command, the senior captain of her Q-ship squadron.
He would have known that tall, athletic figure even without the cream-and-gray 'cat in her arms, and he inhaled deeply as he recognized the broad-shouldered senior captain immediately behind her.
An officer of Truman's caliber, especially one who'd just made the senior captain's list which virtually assured her of future flag rank, might well regard assignment to a Q-ship as a slap in the face.
An officer of Truman's caliber, especially one who'd just made the senior captain's list, which virtually assured her of future flag rank, might well regard assignment to a Q-ship as a slap in the face.