Word: heptathlons
Part of speech: Noun
Syllables: hep
tath
lons
Definition: Plural of heptathlon. An athletic contest comprising seven events; contested mostly by women, for whom this is an Olympic sport.
Morphemes:
Affix: hepta-
Language: en
PoS: Prefix
Meaning: seven
Etymology Compounds: Affix: ἑπτά
Language: grc
Decoded: epta
Meaning: seven
Affix: -athlon
Language: en
PoS: Suffix
Meaning: Contest
Etymology Compounds: Affix: h₂weh₁-
Language: ine-pro
Decoded: h2weh1-
Meaning: to blow 
Affix: -dʰlom
Language: ine-pro
Decoded: -dhlom
Meaning: forms nouns denoting tool or instrument
Affix: -s
Language: en
PoS: Suffix
Meaning: Used to form many pluralia tantum (nouns that are almost or entirely without singular forms).