This is the 1075th most frequent Turkish word.
tekin
Safe, auspicious; free from danger or evil.
'Teksin' is used here to describe a sense of safety and security.
Bu orman geceleri pek tekin değil.
This forest is not very safe at night.
'Teksin' is used here to imply someone being reliable or suitable.
Bu iş biraz tekin birine benzemiyor.
This task doesn't seem to suit someone trustworthy.
'Tek' in this form refers to 'teknique', stemming from 'teksin', though expanded in meaning.