It means a weak point and is an adage.
Many words can be employed to refer to an expression. Most, as you'll see, are true synonyms of one or more others, but a few have specific (and sometimes unique) connotations. Here are the synonyms and their senses:
1. Adage (from the Latin adagium, "proverb") - An often metaphorical observation: "The early bird gets the worm."
2. Aphorism (from the Greek aphorismos, "definition") - A principle concisely stated: "Less is more."
3. Apothegm (from Greek apophthegma, derived from apophthengesthai, "to speak out") - An instructive comment: "Cleanliness is next to godliness."
4. Banality (from the French banal, "commonplace") - A trite comment: "You get what you pay for."
5. Bromide (from the word for a compound, made in part from the element bromine, used as a sedative) - A hackneyed statement: "We have to work together."
6. Byword - A proverb, or a frequently used word or phrase: "You can get more flies with honey than with vinegar."
7. Chestnut (from the Greek kastanea, "chestnut") - A stale saying or story: "There's no such thing as a free lunch."
8. Cliché (from the French word for "stereotype") - An overly familiar expression: "Keep the faith" (or an overdone theme, like moviedom's manic pixie dream girl).
9. Commonplace (from the Latin locus communis, "widely applicable argument") - An obvious but often tiresome or unfortunate comment: "What goes around comes around" (or a trite phenomena, such as drivers sending text messages).
10. Epigram (from the Greek epigramma, derived from epigraphein, "to write on") - A concise and wise and/or clever saying: Time is money."
11. Homily (from the Latin homilia, "conversation") - a catchphrase (or sermon) meant to inspire: "To err is human; to forgive divine."
12. Maxim (from the Latin maxima, the superlative of magnus, "large") - A rule or principle: "A watched pot never boils."
13. Moral (from the Latin moralis, "custom") - The lesson of an instructive story: "Be satisfied with what you have."
14. Motto (from the Latin muttire, "mutter") - A statement of a principle: "Be prepared."
15. Platitude (from the French plat, "dull") - A banal remark: "Blondes have more fun."
16. Precept (from the Latin praeceptum, "something taken before") - A statement of a rule: "Thou shalt not kill."
17. Principle (from the Latin principium, "beginning") - A law or rule of conduct: "It is better to give than to receive."
18. Proverb (from the Latin proverbium, from pro-, "for" or "to," and verbum, "word") - A direct synonym for adage, byword, epigram, and maxim.
19. Saw (from the Old English sagu, "discourse") - A maxim or proverb, often referred to with some condescension: "You've heard that old saw about how to get healthy, wealthy, and wise."
20. Saying - An adage: "Let sleeping dogs lie."
21. Sententia (from the Latin word for "feeling, opinion") - A brief expression of a principle: "To thine own self be true."
22. Shibboleth (from the Hebrew word for "stream," described in The Bible as a word used, by its pronunciation, to distinguish speakers of one region for another) - A widely held belief: "Time heals all wounds."
23. Slogan (from Scottish Gaelic sluagh-ghairm, "war cry") - A statement of a position or goal: "Say what you mean, and mean what you say" (or an advertising statement: "We will not be undersold!").
24. Trope (from Latin tropos, "turn," "way," "manner," "style") - A common figure of speech: "Not that there's anything wrong with that" (or a trite theme, as the climactic duel in a western movie).
25. Truism - An obvious truth: "You can't win them all."
"Heel" can function as both a noun and a verb. As a noun, it refers to the back part of the human foot. As a verb, it can mean to tilt or lean to one side.
The homonym for heel is heal. "Heel" refers to the back part of the foot, while "heal" means to become healthy or whole again.
The part of speech for "answer" is a noun.
The part of speech for this particular word is a noun.
The part of speech for "indefinite" is an adjective.
The part of speech for "buried" is a verb.
His heel
the heel
Toe,heel...
Heel
Thetis dipped Achilles in the waters of the River Styx, by which means he became invulnerable, except for the part of his heel by which she held him-the proverbial "Achilles' heel."
It is the heel bone.
part of speech
The part of speech for this particular word is a noun.
what part of speech is beneath
what part of speech is work
adverb
Achilles' Heel