front rank promachos

[Bryan]

Was there an equivalent Latin version of promachos, those who fight in the front rank?

Closest I can think of are antesignani but I don't think those actually refer to line infantry. Did the Romans actually have a name for the elite who fight in the front ranks?

[Lupianus]

I am under the impression that promachos wasn't a technical term but rather an heroic ideal celebrated by Homer, Tyrtaeus and the likes. Not even sure if it the promachoi were ascribed to close order troops in the first place as they often appear rushing out in search of single combat – IIRC it's Tyrtaeus who also points out the danger of being mistaken for an enemy if you advance too far on your own!
Apparently even more than the Greeks the Romans had a rather ambivalent attitude towards embracing such heroic practice. There are instances of individuals rushing out in front mentioned in Roman literature, too. But these are exceptions to the rule. Actually, I very much doubt if 'front-rankers' were given some kind of elite status, since Roman tactics seem to rely on replacing fallen, wounded or simply exhausted soldiers by equivalent or even better fighters from the rear (think of the Republican hastati-principes-triarii deployment). Therefore heroic action likely would've been 'outsourced' to the advanced lines of skirmishers – that's also proposed in Lendon's 'Soldiers and Ghosts' – and if the antesignani weren't just a 'colour party' but actual skirmishers they could stand in as Roman promachoi.

[Frank]

Well, it makes sense to have the most experienced soldiers in the first line at the beginning of a battle. It is a good guess, that sometimes battles were already won with the first brutal infantry shock attack. Or it forced the enemy to retreat and re-arrange, which gave the romans the time to replace their first lines with fresh soldiers.

But I don't know about a special latin term for these guys. Antesignani are most probably legionaries acting as skirmishers in front of the lines. Replacing the former Velites, if needed. Just if no auxilia is able to do this job. Of course there are tons of theories about these antesignani. One of them speculates, that they are these frontmen. Because the signifer, wearing no shield, was most probably not placed in the very first line. And so the first line is ante signa. But I found the skirmisher theory much more plausible.