The word "komemiyyut" (קוֹמְמִיּוּת) appears only once in the Torah:
אֲנִ֞י יְהוָ֣ה אֱלֹֽהֵיכֶ֗ם אֲשֶׁ֨ר הוֹצֵ֤אתִי אֶתְכֶם֙ מֵאֶ֣רֶץ מִצְרַ֔יִם מִֽהְיֹ֥ת לָהֶ֖ם עֲבָדִ֑ים וָאֶשְׁבֹּר֙ מֹטֹ֣ת עֻלְּכֶ֔ם וָאוֹלֵ֥ךְ אֶתְכֶ֖ם קֽוֹמְמִיּֽוּת׃
I am the Lord your God who brought you out from the land of the Egyptians to be their slaves no longer, who broke the bars of your yoke and made you walk "komemiyyut". [Leviticus 26:13]
It also appears in the siddur, in Ahava Rabbah, before the Shema in Shacharit:
Vehavienu leshalom me-arbah kanfot ha’aretz vetolichenu komemiyyut l’artzenu.
May You bring us together from the four corners of the earth, leading us "komemiyyut" to our land.
We find it also in Birkat Hamazon, the Grace After Meals:
Harachaman Hu yishbor alenu me'al tzavarenu v’Hu yolikhenu komemiyyut le-artzenu.
The compassionate One! May He break the yoke of oppression from our necks and guide us "komemiyyut" to our land.
What does the word mean? Sifra on Bechukkotai 3:7 says it means "erect", and is quoted as such by Rashi, who made that interpretation near-universal.
But the Talmud [Kiddushin 31a] prohibits walking in an upright and haughty manner:
אמר רבי יהושע בן לוי אסור לאדם שיהלך ארבע אמות בקומה זקופה
Rabbi Yehoshua ben Levi says: It is prohibited for a person to walk even four cubits with an upright posture, [considered arrogant], as it says in Isaiah: מְלֹ֥א כָל־הָאָ֖רֶץ כְּבוֹדֽוֹ׃ The entire earth is full of [God's] glory [Isaiah 6:3].
Presumably, he means that walking erect (read: haughtily) insults the honor of God, who is everywhere.
On the other hand, the Talmud [Bava Batra 75a] also says:
Rabbi Meir says [in talking about "komemiyyut" specifically]: [In the future, the Jewish people will be] 200 cubits [tall], equivalent to two [times the] height [komot] of Adam, the first man.
(From koma (height) and me’at (hundreds)?)
I personally don't think Rabbi Meir is talking about physical height, but rather about importance, achievement, influence. (Also, it is impossible for a man to be 200 cubits tall and present the same characteristics as a man, because the universe is not invariant under a change of scale, but ask me separately.) So:
(1) Does "komemiyyut" mean erect or tall? They are different. You can be one but not the other.
(2) Or does it really mean important, prominent, influential, highly productive?