Words Starting With IS
100 wordsWords starting with IS form a compact but scientifically rich corner of English. From the humble two-letter IS to specialized medical and chemical terminology, this pattern showcases how Greek prefixes shaped our technical vocabulary.
2-letter words
13-letter words
34-letter words
55-letter words
86-letter words
87-letter words
158-letter words
169-letter words
2210-letter words
811-letter words
512-letter words
213-letter words
314-letter words
315-letter words
1Pattern Guide
Insights and recommendations for these words.
The IS- prefix carries surprising weight in word games, where Greek-derived scientific terms can unlock impressive scores.
Vocabulary & Language
Linguistic patterns and usage statistics
The Greek prefix 'iso-' meaning 'equal' or 'same' dominates this pattern, generating dozens of scientific terms: isometric (equal measure), isogamy (equal gametes), isochronize (equal time). This single root accounts for much of the pattern's technical character. Outside the iso- family, IS words tend toward basic function words or borrowed terms like ISBA (a Russian log hut).
Total Words
223
0.1% of dictionary
Avg Length
8.9 letters
3.8 syllables
Top Scrabble
ISOCARBOXAZID
34 points
Longest Word
ISOPIESTICALLY
14 letters
Parts of Speech
With 67% nouns and an average length of 8.9 letters, IS words skew heavily toward technical vocabulary. The 29% adjective presence reflects all those scientific -IC endings (ischemic, isometric, isotonic).
Ancient Greek dominates IS words through the iso- prefix, with Proto-Hellenic roots tracing back even further. The etymology of ISOLATE reveals an unexpected path: the word traveled from Latin 'insulatus' (made into an island) through Italian and French before reaching English. The connection between isolation and islands persists in how we conceptualize separation.
Word Games
High-value words for board games
Short (2-4)
Medium (5-7)
one of the three sections of the hipbone; situated below the ilium
(biology) reproduction by the union or fusion of gametes of the same size and structure
Long (8+)
a monoamine oxidase inhibitor (trade name Marplan) that is used to treat clinical depression
Short (2-4)
Medium (5-7)
one of the three sections of the hipbone; situated below the ilium
(biology) reproduction by the union or fusion of gametes of the same size and structure
Long (8+)
a monoamine oxidase inhibitor (trade name Marplan) that is used to treat clinical depression
ISOCARBOXAZID tops both games with its rare X and Z combination—34 points in Scrabble, 36 in WWF. The Z scoring difference (10 points in Scrabble vs 10 in WWF) keeps these games close for IS words. ISCHIUM deserves attention: at 14 Scrabble points versus 16 in WWF, the H's doubled value in WWF (4 vs 2) makes anatomical terms more valuable there. For shorter plays, ISBA offers solid efficiency at 6-7 points for just four letters.
Wordle
5-letter words for daily puzzles
Good Starters (E, A, R, S, T)
a small island
Common Words (likely answers)
a phenomenon that follows and is caused by some previous phenomenon
a small island
ISLET and ISTLE both test the common consonants S, T, and L while checking different vowel positions. ISLET places the E in a frequent fourth-position spot, making it slightly more diagnostic for standard English words.
Length Extremes
Longest and shortest valid words
The prevalence of long IS words stems from scientific compounding—Greek roots stack predictably (iso- + chron- + -ize + -ing). Short IS words are rare because the pattern naturally leads into prefixed constructions.
Hidden Gems
Rare but valid words to surprise opponents
a volcanic island (part of Campania) in the Tyrrhenian Sea at the north end of the Bay of Naples
muscle-building exercises (or a system of musclebuilding exercises) involving muscular contractions against resistance without movement (the muscles contracts but the length of the muscle does not change)
relating to or affected by ischemia
a policy of nonparticipation in international economic and political relations
ISCHIA names the volcanic island in Italy's Bay of Naples, near Capri. Beyond its geographic interest, it's the plural of ischium (the hip bone section), giving you flexibility—play it as anatomy or geography depending on your opponent's challenges.
Popular crossword answers
Words frequently used in crossword puzzles with common clues.