Interesting Affixes: IN-

When IN doesn't always mean in...

One of the most common prefixes in the English language happens to be one that has multiple meanings that are mostly but not always understood. We usually encounter the prefix IN- in two different contexts.

In many words, this prefix asserts its prepositional privilege, meaning in, into, or upon. We’ve featured a number of these words over the years:

• inception

• incipient

• inculcate

• inflection

• ingratiate

• inundate

However, as one might expect from a species as contrary as Homo sapiens, we have many more instances where IN- is used as a contrast or contradiction meaning not:

• incessant

• incongruous

• incredulous

• indignant

• indispose

• indolent

• inexorable

• infallible

• inimical

• intractable

The rarest and likely most confusing IN- words occur when the prefix is used as an intensifier or agreement rather than a contrast. Three common English words deserve special attention because of how misleading their prefixes can seem:

The word inflammable does NOT mean not flammable:

• inflammable (adj) - capable of burning; easily ignited or excited (same as flammable)

  BREAKDOWN: IN- (in) + FLAM- (flame) + -ABLE (able to be)

The word ingenious does NOT mean not a genius:

• ingenious (adj) - clever, resourceful, original and inventive; having genius
  BREAKDOWN: IN- (in) + GEN- (birth) + -OUS (full of)

The word invaluable does NOT mean not valuable, even though the prefix really does mean not:

• invaluable (adj) - extremely valuable or useful; priceless
  BREAKDOWN: IN- (in) + VAL- (worth) + -ABLE (able to be)

“Books of quotation are not only of importance to the reader for what they contain of matured thought, but also for what they suggest. Our brains receive the spark and become luminous, like inflammable material by the contact of flint and steel.” –Maturin Murray Ballou