Kangaroo words
A kangaroo word contains a synonym of itself, spelled out in order among its own letters. BLOSSOM contains BLOOM. MASCULINE contains MALE. The smaller word is called the joey.
Words that contain their own synonym
Two rules do all the work. The joey's letters have to appear in order, and the joey has to mean roughly what the larger word means.
The order rule is looser than it sounds, because the letters need not sit together. BLOOM is spelled out by the B, the L and the first O of BLOSSOM, then the O and M at the end. The synonym rule is where almost every candidate fails. Long words contain short ones constantly — CARTON contains CART, PLANET contains PLAN — but the short word hardly ever means the same thing. Published collections run to a few hundred pairs, which is a thin return on a dictionary of well over a hundred thousand words.
Examples
- BLOSSOM BLOOM
- MASCULINE MALE
- CURTAIL CUT
- RAPSCALLION RASCAL
- CATACOMB TOMB
- ENCOURAGE URGE
- PRECIPITATION RAIN
- DECEASED DEAD
- FRAGILE FRAIL
- INSTRUCTOR TUTOR
- PROSECUTE SUE
- DESTRUCTION RUIN
Relatives and coincidences
Some pairs are genuinely related and some are not, and you cannot tell which by looking. MASCULINE and MALE both descend from Latin masculus. CURTAIL and CUT have nothing to do with each other: CURTAIL comes from curtal, a horse with a docked tail, and the synonym inside it is an accident of spelling. Across the pairs written for this game so far, 101 are related and 67 are pure coincidence; the remaining 21 nobody has settled.
Twins and anti-kangaroos
Collectors name a few variants. A twin carries two joeys at once: CONTAINER holds both CAN and TIN. An anti-kangaroo carries its own opposite instead of its synonym — ANIMOSITY holds AMITY. Hidden Joey uses only the plain form.
Where the name came from
No one can point to a first use. The oldest appearance anyone can actually cite is a 1954 Reader's Digest puzzle piece by Ben L. O'Dell, said to be reprinted from The American Magazine a few years earlier. The sources that mention him credit him with defining and popularising the term, not inventing it, and no dictionary carries an entry that would settle it. The 1956 date that circulates online contradicts itself: it comes after the reprint it is supposed to have produced. Mid-century American puzzle columns are the likeliest home for the name, and it stuck.
And the kangaroo itself
Kangaroo entered English from Guugu Yimithirr gangurru, written down at the Endeavour River in 1770 while Cook's ship was beached for repairs. The familiar story that it really means "I don't understand" is folklore: John Haviland's fieldwork with Guugu Yimithirr speakers in the 1970s confirmed gangurru as a real word for a large kangaroo species.
What counts here
This game sets the bar at three things. The joey's letters appear in order. The joey is a synonym a thesaurus will back, not one you have to argue for. And a word hiding its own stem — LATEST hiding LATE — counts for less than a word hiding a different word, the way CATACOMB hides TOMB.
Hidden Joey is a free daily game about these words: three rounds a day, and every round ends with the true story of where its word came from.