Refers to a person who deceives others for money, especially in gambling or confidence tricks. Often carries a slightly old-fashioned or theatrical tone.
He was tricked by a con artist and lost a large sum of money.
That man is a swindler who uses sleight-of-hand tricks.
詐欺師 is a more modern and legal term for a fraudster or scammer, while いかさま師 has a more colloquial, old-fashioned feel, often associated with street cons or gambling cheats.
ペテン師 is a near-synonym for a swindler or con man, but いかさま師 emphasizes the act of cheating itself (いかさま), whereas ペテン師 comes from 'peten' (trickery) and can sound slightly more dated or literary.
Standard kanji-kana mixed spelling; 師 means 'master' or 'specialist'.
Full kanji spelling using ateji for いかさま; rarely used in modern writing.
いかさま is a word meaning 'fraud' or 'cheating', of uncertain origin, possibly related to いかが (how) or a contraction of いかがさま. 師 is a suffix meaning 'master' or 'specialist', so the compound literally means 'master of cheating'.