Let’s look at this very used and useful Gothic word. Its meaning is pretty clear. From corresponding words in Latin and Sanskrit, we get the meaning to turn, and in analogy with the English word, wairþan is used in expressions like “turn into X”. It is still used in many Germanic languages in one form or another. For example Svensk Etymologisk Ordbok mentioned that the Scanian expression ʋuren (how something turns out relative to expectations) is a form of the perfect participle.
Common uses are:
1. to become
Ïbai jah jus wileiþ þamma siponjos wairþan? — John 9:27.
If even you want his disciples to become(?)
blindai ussaiƕand, jah haltai gaggand — Matthew 11:5.
blind see, and lame walk
Great, but how do we say leprous encleanify? We don’t. Like in English we rewrite it with a helping verb — namely wairþan:
blindai ussaiƕand, jah haltai gaggand, þrutsfillai hrainjai wairþand
2. to describe stochastic outcomes, mainly nature
Wegs mikils warþ ïn marein, swaswe þata skip gahuliþ wairþan fram wegim — Matthew 8:24.
Wave high there was at sea, so the ship covered to be(come) by waves
Another example of this use is the fixed expression warþ þan which is very useful for story telling. It occurs 15 times in the gospels:
The table shows the text of Wescott&Hort’s Alexandrian Greek edition, Robinson & Pierpont’s Byzantine Greek edition, the Eastern Classical Syriac Peshitta and the Old Classical Syriac Sinaitic Palimpsest respectively, in the places where the Gothic version has warþ þan.