'Ig-fold-like' originates from English, composed of the abbreviation 'Ig' (short for 'immunoglobulin'), the noun 'fold' (a protein folding motif), and the suffix '-like' meaning 'similar to'.

'Immunoglobulin' was coined in the 20th century from 'immune' (from Latin 'immunis') + 'globulin' (from Latin 'globulus' via 'globule'); the abbreviation 'Ig' arose in biochemical literature in the mid-1900s. The word 'fold' derives from Old English 'fealdan' meaning 'to fold' and came into Modern English as 'fold' to denote folded structures; the suffix '-like' descends from Old English '-lic' (via Middle English) and developed into the productive modern suffix '-like' meaning 'similar to'.

The compound originally served to indicate similarity to the 'immunoglobulin fold'; over time it has become a concise adjectival descriptor in structural biology specifically used for protein domains that share that β-sandwich topology.