"Well, I don't tease anybody but the men. I don't tease father or mother or you,—but men are fair game; they are such thumby, blundering creatures, and we can confuse them so."

[…] he was propounding an improvement of Professor Armstrong's Heuristic method, whereby at the cost of three or four hundred pounds' worth of apparatus, a total neglect of all other studies and the undivided attention of a teacher of exceptional gifts, an average child might with a peculiar sort of thumby thoroughness learn in the course of ten or twelve years almost as much chemistry as one could get in one of those objectionable shilling text-books that were then so common….

The box was set down, the stiff buckles of its mildewed straps tackled by a dozen thumby hands, the lid hurled back.

For as long as we have known him—and for most of us that has been for the lengths of our lifetimes—he has been the object of, and inspiration for, a delight so innocent and perfect that the attempt to analyse its sources seems an act of ingratitude, a laying on of thumby hands that will inevitably bollix the job.

Some people are handy, but I am (no other word fits) thumby.
The handy learn to master each moder machine as soon as it hits the market. The thumby never graduate beyond the self-service island at the gas station.

2015, Julie Lawson, A Ribbon of Shining Steel: The Railway Diary of Kate Cameron, Yale, British Columbia, 1882, Dear Canada series, Scholastic Canada, https://books.google.ca/books?id=h1X2CQAAQBAJ&printsec=frontcover#v=onepage&q&f=false
Rachel was all thumbs when it came to embroidery, even thumbier than me.

He would distinguish, too, between a library and a news-room, and would find no great attraction in the prospect of supplying the national youth with free but thumby copies of the sixpenny magazines.

Thumby

Meaning

Noun

Adj

Synonyms