I'll go with warship since no one's voted for that one yet. It has been referenced as a warship a higher number of times by my count. Although it is referred to as a fighter in more episodes
Jem'Hadar attack ship - said 6 times in 6 episodes
Jem'Hadar fighter - said 11 times in 9 episodes
Jem'Hadar warship - said 13 times in 7 episodes
Jem'Hadar patrol ship - said 1 time in 1 episode
A Time To Stand
DAX: It's a Jem'Hadar attack ship.
Blaze of Glory
SISKO: Suit yourself. Maybe it's nothing. It is hard to get an accurate sensor reading in the Badlands. But unless I'm mistaken, two Jem'Hadar warships are headed our way.
EDDINGTON: Yeah, those are Jem'Hadar warships all right. You've got a problem.
Far Beyond The Stars
KIRA: Patrolling the Cardassian borders is getting more and more dangerous. You never know when you're going to run into a squadron of Jem'Hadar fighters.
SISKO: I realise that, but the Dominion is getting bolder and bolder, and your freighter is no match for a Jem'Hadar attack ship.
Field of Fire
BASHIR: I was speaking metaphorically. This inspired cherub masterfully piloted the Defiant into battle against a half dozen Jem'Hadar attack ships, and once all the smoke had cleared, only one ship remained intact, and that, ladies and gentlemen, was the USS Defiant.
In Purgatory's Shadow
GARAK: Well I certainly don't want to take an unnecessary risk, but our sensors show no sign of Jem'Hadar warships in this area.
Rocks And Shoals
Captain's log, supplemental. O'Brien needed three days to restore main power to our commandeered Dominion ship, but he's not going to get them. Sensors have detected two Jem'Hadar fighters heading our way, and without main power our chances of survival are slim to none.
Sons And Daughters
ALEXANDER: Jem'Hadar attack ship bearing one seven zero mark zero four five. Estimated weapons range in twenty two seconds.
Tears Of The Prophets
SISKO: Five squadrons of Jem'Hadar attack ships. At the moment, that's the entire Dominion fleet protecting the Chin'toka system.
KIRA: Jem'Hadar fighters approaching, bearing zero five nine mark zero three one.
MARTOK [OC]: My attack wing is closest to those Jem'Hadar fighters. Preparing to engage.
Treachery, Faith and the Great River
DAMAR: I don't know what you're so concerned about. Odo couldn't possibly hope to outrun a Jem'Hadar attack ship.
DAMAR: I don't understand it. How could a runabout destroy a Jem'Hadar fighter?
The Die Is Cast
PILOT: Jem'Hadar fighters.
KIRA: The third Jem'Hadar fighter is still pursuing.
Valiant
NOG: Not in a runabout we're not. We're no match for a wing of Jem'Hadar fighters.
Once More Unto The Breach
KOLANA: Their warp signatures are bearing directly astern. They're Jem'Hadar fighters and they appear to be pursuing us.
Soldiers of the Empire
WORF [OC]: Alert status one. A Jem'Hadar patrol ship is directly ahead. Prepare for combat operations.
MARTOK: There are probably five Jem'Hadar warships out there right now just waiting for us to cross the border.
TAVANA: Tactical alert! Tactical alert! There is a Jem'Hadar warship bearing one eight zero mark two one five. They will be within weapons range in nine minutes.
Starship Down
CARSON: Two ships have just entered sensor range. They're Jem'Hadar warships.
Tacking Into The Wind
GARAK: And according to our new contact on Kelvas Five, the Breen will begin to install their energy dampening weapons aboard Jem'Hadar fighters within a week.
Penumbra
EZRI: They're Jem'Hadar fighters.
The Search, part 1
O'BRIEN: Commander, long range scanners have picked up two Jem'Hadar warships directly ahead. They're heading this way at warp five.
BASHIR: Commander, three more Jem'Hadar warships approaching off the port bow!
The Ship
WORF: A warship. A Jem'Hadar warship.
HOYA [OC]: A Jem'Hadar warship
DAX: Chief, structurally, a lot about this ship's design matches the other Jem'Hadar warships we've seen.
To The Death
WORF: A Jem'Hadar warship. This can't be the vessel we're looking for. Major Kira said the Jem'Hadar strike team that attacked the station used a transport ship.
SISKO: Why do you need my help? You could send a whole fleet of Jem'Hadar warships after them.