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in-¹ or il- or im- or ir-

pref.

Not: inarticulate. Before l, in- is usually assimilated to il-; before r to ir-; and before b, m, and p to im-. See Usage Note at un-¹.

[Middle English, from Old French, from Latin; see ne in the Appendix of Indo-European roots.]

in-² or il- or im- or ir-

pref.

1. In; into; within: inundation. Before l, in- is usually assimilated to il-; before r to ir-; and before b, m, and p to im-.

2. Variant of en-¹.

[Middle English, from Old English (from in, in; see IN¹) and from Old French (from Latin, from in, in, within; see en in the Appendix of Indo-European roots).]

Indo-European & Semitic Roots Appendices

Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

Indo-European Roots

Semitic Roots

The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

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