As we know, the eldest of the Pandavas is Yudhishthira (IAST : Yudhiṣṭhira and Devanagari: युधिष्ठिर). It is said that he got his name due to his steadiness in war. This is also a famous one. From related Wikipedia article:
The word Yudhishthira means "the one who is steady in the war", from the words, yuddha (युद्ध) meaning 'war', and sthira (स्थिर) meaning 'steady'.
The article doesn't provide any citations for the claim.
He is known for his steadiness in a miserable situation like Yaksha prashna where all of his brothers were lying dead in front of him. Yet he answered all the questions correctly and brought back his brothers back to life.
But there is an incident during the Kurukshetra where Yudhishthira lost his cool head and thought of retiring to woods. This happened after the ninth day war. Yudhishthira says the following to Krishna.
'Behold, O Krishna, the high-souled Bhishma of fierce prowess. He crusheth my troops like an elephant crushing a forest of reeds. ....... When this is the case, O Krishna, I am, through the weakness of my understanding, plunged in an ocean of grief having got Bhishma (as a foe) in battle. I will retire into the woods, O invincible one. My exile there would be for my benefit. Battle, O Krishna, I no longer desire. Bhishma slayeth us always. As an insect, by rushing into a blazing fire meeteth only with death, even so do I rush upon Bhishma. In putting forth prowess, O thou of Vrishni's race, for the sake of my kingdom, I am, alas, led to destruction. My brave brothers have all been exceedingly afflicted with arrows. In consequence of the affection they bear to myself their (eldest) brother they had to go into the woods, deprived of kingdom. For myself alone, O slayer of Madhu, hath Krishna been sunk into such distress. I regard life to be of high value. Indeed, even life now seemeth to be difficult of being saved. (If I can save that life), its latter remnant will I pass in the practice of excellent virtue. [Mahabharata Bhishma Parva Chapter 18]
These are the words of Yudhishthira during the Kurukshetra battle. If the etymology of his name correct, then he should be steady in the war.
The Sambhava Parva of Adi Parva doesn't give the reason he is named such. It simply says that he is named as Yudhishthira.
O king, after all the children were born the Rishis dwelling on the mountain of a hundred peaks uttering blessings on them and affectionately performing the first rites of birth, bestowed appellations on them. The eldest of Kunti's children was called Yudhishthira, the second Bhimasena, and the third Arjuna, and of Madri's sons, the first-born of the twins was called Nakula and the next Sahadeva. And those foremost sons born at an interval of one year after one another, looked like an embodied period of five years.
So, my question is whether the etymology of the name Yudhishthira the same as given in the Wikipedia article or is there any other reason?
Is the etymology of this name mentioned in the Mahabharata like that of Ajata shatru?