Tech trees

[Ranika]

As Neongod said, it's colloquial. Meaning it's local expression. A broadsword, for example, is technically just a one-handed sword with a blade slightly wider than its contemporary equivalents, which were most rapiers and similar. The schianova (German backsword), anracleigh (Irish backsword), arucludd (Scottish broadsword) are all 'broadswords', in this meaning of the word. However, broadsword was also applied, earlier, to swords with a wide (broad) lower portion that tapered to a point in a triangular fashion. Ergo, 'longsword' (which does appear in languages of the period in a literal sense) in this time period simply means a sword longer than other contemporary weapons. Since most swords of the era are comparatively short, swords like the athclwth (Welsh-Norse imitation sword), cleighda (Irish indigenous 'long' swords) the lannlinda (Scot-Pict; it's literally 'Blade-Long', an imitation of Anglo-Saxon swords), spatha (old Roman cavalry swords; adopted as infantry swords too, and used widely in various imitations and variants in much of Europe; an outgrowth of late continental Celtic and then German swords) the many variants of viking swords, are all 'longswords', on the merit that they have longer blades.