“CRUMBUMS” is a valid word. — 16 points Scrabble

scrubdense vegetation consisting of stunted trees or bushes
crumba very small quantity of something
mucusprotective secretion of the mucus membranes; in the gut it lubricates the passage of food and protects the epithelial cells; in the nose and throat and lungs it can make it difficult for bacteria to penetrate the body through the epithelium
scrum(rugby) the method of beginning play in which the forwards of each team crouch side by side with locked arms; play starts when the ball is thrown in between them and the two sides compete for possession
curbsan edge between a sidewalk and a roadway consisting of a line of curbstones (usually forming part of a gutter)
rubuslarge genus of brambles bearing berries
mumus

scumworthless people
cubsan awkward and inexperienced youth
curban edge between a sidewalk and a roadway consisting of a line of curbstones (usually forming part of a gutter)
bumsa person who is deemed to be despicable or contemptible
rubsan unforeseen obstacle
mumsof China
cursan inferior dog or one of mixed breed
mumu
rumsliquor distilled from fermented molasses
uruslarge recently extinct long-horned European wild ox; considered one of the ancestors of domestic cattle
crusthe leg from the knee to foot
bursseed vessel having hooks or prickles
urbs

mumof China
busa vehicle carrying many passengers; used for public transport
buma person who is deemed to be despicable or contemptible
ruban unforeseen obstacle
suma quantity of money
suba large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States
rumliquor distilled from fermented molasses
umm
cuban awkward and inexperienced youth
cumthe thick white fluid containing spermatozoa that is ejaculated by the male genital tract
curan inferior dog or one of mixed breed
mustype genus of the Muridae: common house mice; the tips of the upper incisors have a square notch
burseed vessel having hooks or prickles
urb

usNorth American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776
um
mma metric unit of length equal to one thousandth of a meter
muthe 12th letter of the Greek alphabet

CRUMBUMS