15-Letter Words

100 words

Fifteen-letter words represent the upper limit of what most word games allow on a standard board. These linguistic marathons pack entire concepts into single terms, from medical conditions to philosophical states. Here you'll find words that stretch across nearly the full width of a Scrabble board.

Words starting with A

4

Words starting with C

9

Words starting with D

15

Words starting with E

7

Words starting with G

1

Words starting with H

2

Words starting with I

14

Words starting with M

6

Words starting with N

3

Words starting with O

2

Words starting with P

14

Words starting with R

4

Words starting with S

6

Words starting with T

3

Words starting with U

9

Words starting with W

1

Pattern Guide

Insights and recommendations for these words.

At fifteen letters, you're working with words that most players never encounter in competitive play. Understanding their structure reveals patterns that apply to shorter, more practical words too.

Vocabulary & Language

Linguistic patterns and usage statistics

Words this long almost always feature multiple affixes stacked onto a core root. Prefixes like HYPER-, DE-, and EX- combine with suffixes like -IZATION, -ICALLY, and -ACEOUS to extend base words far beyond their origins. Many 15-letter words are technical terms from medicine and science, where precision demands combining Greek and Latin elements into single descriptive compounds.

Total Words

1,844

0.6% of dictionary

Top Scrabble

OXYPHENBUTAZONE

41 points

Parts of Speech

Nouns
75%
Verbs
1%
Adjectives
18%
Adverbs
6%

Latin and French dominate the origins of these lengthy words, which makes sense given their role as the historical languages of science and scholarship. The chain from CEPHALOCHORDATE back through Ancient Greek κεφαλή to Proto-Indo-European *gʰebʰ- shows how scientific terminology often preserves ancient roots. English absorbed these scholarly terms wholesale rather than translating them.

Word Games

High-value words for board games

Top 15-Letter Words

OXYPHENBUTAZONE

an anti-inflammatory drug (trade name Tandearil) used to treat arthritis and bursitis

41 pts
ZYGOPHYLLACEOUS
38 pts
HYPERIMMUNIZING
37 pts
HYPNOTIZABILITY
37 pts
HYPERPHYSICALLY
36 pts
MONOPHTHONGIZED
36 pts
DEMYTHOLOGIZING
35 pts
EXPERIMENTALIZE
35 pts

OXYPHENBUTAZONE tops both Scrabble and WWF charts, but the real strategic differences emerge in the mid-tier words. COMMERCIALIZING scores 40 points in WWF but significantly less in Scrabble due to WWF's boosted tile values. HYPERIMMUNIZING gains extra leverage in WWF where both H and Z carry more weight. Since 15-letter words require a nearly empty board or perfect alignment, knowing which game rewards specific letters helps you prioritize bonus square placement.

Hidden Gems

Rare but valid words to surprise opponents

ACCLIMATISATION

adaptation to a new climate (a new temperature or altitude or environment)

ATHEROSCLEROSIS

a stage of arteriosclerosis involving fatty deposits (atheromas) inside the arterial walls, thus narrowing the arteries

CIRCUMFERENTIAL

lying around or just outside the edges or outskirts

"circumferential highways around cities"

COMMUNICATIONAL

used in communication

"he had few communicational grooves available for use"

CIRCUMFERENTIAL means lying around or just outside the edges or outskirts of something. Beyond its geometric precision, this word demonstrates how Latin's circum- (around) combines with ferre (to carry) to create spatial concepts. It's the kind of technical term that appears in engineering and anatomy texts but remains valid in word games.

Popular crossword answers

Words frequently used in crossword puzzles with common clues.