Words similar to doubtful

Example sentences for: doubtful

How can you use “doubtful” in a sentence? Here are some example sentences to help you improve your vocabulary:

The effectiveness of such disinfection practices or environmental background monitoring has not been documented, and is likely of doubtful public health utility.
If a lesion was considered a putative precancer (even when the evidence seemed doubtful), it was added to the taxonomy.
In Button's case, it's particularly doubtful given his tendencies toward dumb, impulsive action revealed in his records.
It is doubtful that in conversation he would ever remark, “Up early ...”
A fee is charged for the doubtful privilege of a visit — making monkeys out of the tourists has been a local source of amusement and income for years.