Thank you, Webster, for the most
illuminating snippet that palatalize means palatize. This latter word is never used in
linguistics now.
To palatalize is to affect a consonant so that it is pronounced closer to the palate (viz the soft palate), or it gains a secondary articulation at the palate in addition to its primary articulation.
Palatalization typically occurs near a front vowel such as i, in which the tongue approaches the palate. For example, English k in king has a sound more like ky than it does in khan or kook. In time this can radically change a sound, e.g. the palatalization of C, the Latin k-sound, causing it to take on the strikingly different sounds of French, Italian, or Spanish CE and CI, as compared to CA, CO, or CU.
In Japanese any consonant followed by i is palatalized, and is pronounced the same as if followed by y, e.g. the syllables NI, NYA, NYO, NYU share the same initial sound.