What are the four common English words ending in “-dous”?

Dear Cecil: Isaac Asimov posed a puzzle in a magazine and I’m going crazy trying to figure out the answer. He said there are only four commonly used English words that end in -dous. Two are “positive” and two are “negative.” The positive ones are tremendous and stupendous, and one of the negatives is horrendous. What is the fourth word? Adam R., Baltimore

Cecil replies:

The late Isaac may have thought there was only one other word, but around here we figure a man’s reach should exceed his grasp. I’ll give you two words — hazardous and timidous. What do you mean, timidous isn’t common? Timid, timider, timidous. What could be commoner than that?

The last word

Dear Cecil:

Re the four or five English words ending in -dous, did you forget “jeopardous”?

— M.H. Carter, Jacksonville, Florida

No. To forget something you have to have heard of it in the first place, which frankly I hadn’t, mainly because the last cited use of jeapardous in the Oxford English Dictionary was in 1661. (“Yo, varlet, is the new quiz show ‘What’s My Linish’ or ‘Wheel of Fortunesque’?” “Neither, milord, it is ‘Jeopardous.’”) So sue me.

All right already

Dear Cecil:

Re the four or five English words ending in -dous, you forgot at least a dozen more, as the enclosed xerox from Walker’s Rhyming Dictionary (1936) clearly indicates. The words are vanadous, molybdous, mucidous, multifidous, nefandous, frondous, decapodous, lagopodous, tylopodous, steganopodous, heteropodous, gasteropodous, isopodous, and ligniperdous.

— Hugh R., department of physics, University of Wisconsin at Madison

Dear Cecil:

… amphipodous, apodous, blizzardous, gastropodous, hybridous, iodous, nodous, octapodous, palladous, paludous, pudendous, rhodous, sauropodous, schizopodous, solipedous, splendidous, tetrapodous, voudous …

— Philip C., White Plains, New York

Very impressive, guys. But don’t expect to get invited on any long fishing trips with me.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.