Question: What does hidâyah mean?
ANSWER
It has such senses: to enter the true path after seeing right as right and wrong as wrong; to guide one to the true path; to turn away from dalâlah [deviation, going astray] and false paths; to have îmân and to become a Muslim; a guide; the Qur’ân; tawhîd.

Hidâyah means guiding a person to the true path; being on the path Allahu ta’âlâ is pleased with; Allah’s purging one’s heart from all the gloom, distress and supplying it with comfort and expansion instead, thus granting complete easiness in observing His commandments and prohibitions; His subjugating a born slave’s contentment to His qadâ and qadar. As for the meaning of “ihtidâ,” it is to attain hidâyah, that is, to become a Muslim, to choose Islam as one’s religion.

The parts added in square brackets to the purport of undermentioned verses are explanatory statements from tafsîr books:
(Our Lord is He Who grants a distinctive feature to everything and then gives hidâyah [Who guides towards the true path].) [Sûrat-u Tâhâ, 50]

(We made them all [Ibrâhîm, Ishâq, Ya’qûb] imâms [guides] who would show hidâyah [the true path, Islam] by Our command [revelation]. We revealed to them the doing of good deeds, the performance of namâz correctly, the giving of zakât. They were the persons who worshipped Us [they were not idolaters].) [Sûrat-ul-Anbiyâ’, 73]

(Allah guides whom He wills to the right path.) [Sûrat-ul-Baqara, 213]

(Those who accepted hidâyah [those who became Muslims by having îmân], Allah increased their hidâyah [their success in the true path, their obeying Islam] and inspired [explained] them the remedies for bewaring of evil.) [Sûrat-u Muhammad, 17]

(Whoever believes in Allah, Allah guides his heart to hidâyah [truth, Islam].) [Sûrat-ut-Taghâbun, 11]

(The dwellers of Jannah, beneath which rivers flow, say, “Praise be to Allah Who has made us attain to this with His hidâyah [by making us Muslims]. Had Allahu ta’âlâ not given us hidâyah [had He not made us Muslims], we could not have found this path on our own.) [Sûrat-ul-A’râf, 43]

(Those who believe and do pious deeds; because of their belief, their Lord guides them to Jannats [puts them in Jannats], beneath which rivers flow and which abound with blessings.) [Sûrat-u Yûnus, 9]

(O My Messenger, say: Whoever is an enemy to Gabriel is an enemy to Allah because he, by Allah’s leave, has brought down the Qur’ân to your heart as a confirmer of the books sent before it, as a hidâyah [guide], and as a bearer of glad tidings.) [Sûrat-ul-Baqara, 97]

(When we listened to the hidâyah [the Qur’ân], we believed in it.) [Sûrat-ul-Jinn, 13]

(Allah does not give hidâyah [does not guide to the true path] to those who commit zulm [to those who take disbelievers for their friends and thus who do injustice to themselves].) [Sûrat-ul-Mâida, 51]

(He leaves in deviation whom He wills, and He guides to hidâyah [the true path, Islam] whom He wills.) [Sûrat-ul-Fâtir, 8]

(Allah guides to hidâyah [guides to Islam] whom He wills; He leaves in dalâlah whom He wills.) [Sûrat-u Ibrâhîm, 4]

(We have sent down this Book to you so that you explain the controversial matters to them, and as a hidâyah [a guide showing the true path] and mercy for those who believe.) [Sûrat-un-Nahl, 64]

(Those who disbelieve the liqâ-Allah [meeting Allah] and thus who stay away from hidâyah [from Islam, which is the true path] will certainly suffer the greatest loss.) [Sûrat-u Yûnus, 45]

(Hidâyah is only Allah’s hidâyah [the true path is only Allah’s path].) [Sûrat-ul-Baqara, 120]

(Those are the ones to whom Allah has given hidâyah [whom Allah has made attain to Islam].) [Sûrat-uz-Zumar, 18]

(Allah increases the hidâyah [their devotion to Islam] of those who have attained it [who have îmân and become Muslims].) [Sûrat-u Maryam, 76; Sûrat-u Muhammad, 17]

(He makes them attain to hidâyah [He makes them attain to îmân].) [Sûrat-u Muhammad, 5]

(They bought dalâlah instead of hidâyah [the true path].) [Sûrat-ul-Baqara, 175]

(Allah has sent His Messenger with Islam, which is hidâyah and the true religion. He has made Islam superior over other religions. Allah suffices as a witness that He is a Prophet [that Muhammad “alaihis-salâm” is the True Prophet].) [Sûrat-ul-Fath, 28]