It's plausible that "agile gibbon" is a single term in that dictionary; cf. the Wikipedia article for "agile gibbon": https://en.wikipedia.org/wiki/Agile_gibbon

It's plausible that "agile gibbon" is a single term in that dictionary; cf. the Wikipedia article for "agile gibbon": https://en.wikipedia.org/wiki/Agile_gibbon https://en.wikipedia.org/wiki/Agile_gibbon Note also the other transformations involving headwords that contain spaces: "civil war" -> "clabber", "starship" -> "starting pistol", "custodian" -> "customs union", and "galaxy" -> "galia melon". I don't know what dictionary is being used: the post just says "I used a 1999 Oxford English dictionary" but I doubt it's the full OED, as in it "agent" is followed by (I think) entries for "agent provocateur", "agentess", "agential", "agentive", "agentship", "ageold", "ageometrical", "ageostrophic", "age-prier", "ager", "agerasia", "ageratum", … [lots of "agg…" words]… and "agile gibbon" would be very far away. Edit: For example, The New Oxford Dictionary of English (1998: not OED but ODE: https://en.wikipedia.org/wiki/Oxford_Dictionary_of_English https://en.wikipedia.org/wiki/Oxford_Dictionary_of_English) has "agile gibbon" as a separate entry in the dictionary, though it is 27 places after "agent" rather than 7.