Given that immortality is a word with a reasonably clear definition using a modifier like ‘literal’ or ‘actual’ (but, as you say, definitely not ‘true’) would be sufficient. Especially when the ‘other words’ are in the previous sentence.
Incidentally… the claim seems just wrong. You don’t need WBE to achieve immortality. Although at the level of technology required to achieve something sufficiently reliable as to be called immortality without WBE the WBE tech would probably be comparatively trivial.
Given that immortality is a word with a reasonably clear definition using a modifier like ‘literal’ or ‘actual’ (but, as you say, definitely not ‘true’) would be sufficient. Especially when the ‘other words’ are in the previous sentence.
Incidentally… the claim seems just wrong. You don’t need WBE to achieve immortality. Although at the level of technology required to achieve something sufficiently reliable as to be called immortality without WBE the WBE tech would probably be comparatively trivial.