The explanation or translation of one set of terms with another set of terms, where the second set is typically written between the lines of the text written with the first set.
An interlinear gloss is a way of presenting language data. In academic usage, it typically consists of at least three lines of text (but can be restricted to two lines):
A transcription of the utterance, broken up into the separate morphemes (with hyphens to indicate these are bound morphemes and not separate words);
The interlinear gloss is then on the line below this and has glosses/translations of each morpheme, each aligned with the language data morpheme above;
The third line will usually contain a free translation of the utterance. This is as natural a translation as possible, so cannot be aligned with the preceding lines.
Interlinear glosses are the standard way of presenting linguistic data as it facilitates understanding of unfamiliar data and clearly presents morphosyntactic analysis. Interlinear glosses may have extra lines containing information on aspects such as: phonetics, tone, discourse, etc.
Following are some examples of interlinear glossing:
(1) Zànhe sí dùfugé kɛ̀ ɛ̀ gɛ̀ rain go maize.DEF spoil "The rain will spoil the maize." (from Sùpyìré, Niger-Congo family)
(2) a na taa 3sg come go "He/she will go." (Bambara, Niger-Congo family)
(3) musa’ m -nbu’ yaya’ =mu IRR AF -ill mother =1S.GEN "My mother will be ill" (Squliq Atayal, Austronesian family, Taiwan)