Having the bill straight, as a bird; rectirostral.
The Century Dictionary (Public Domain)
Use "straight-billed" in a sentence
"I find a spot with a stand outside lined with straight-billed caps that are in plain colors, from black to pink, with the elaborate skull-and-flower Ed Hardy–esque designs that are in style right now among some of the tepiteños, and knockoff caps for certain American teams: NY, LA, AZ, and SD, the insignia used by the San Diego Padres."
"Tom Tallington looked eagerly at the straight-billed, long-legged, black-and-white bird, but shook his head, while Chip, the dog, who had seated himself with his nose close to the bunch, uttered one short sharp bark."
" By this point, The End was pretty overrun with youngsters in straight-billed caps, suspenders, plugs and/or flashy sneakers, but hell, we were already three sheets, and the crowd made for an energetic response to Turbo Fruits 'now-familiar material."