Hijab is a word that indicates not just the headscarf but clothing in its entirety which meets the following conditions :
1. Clothing must cover the entire body, only the hands and face may remain visible (Quran An-Nur 24:31 ” Say to the believing women that they should lower their gaze and guard their modesty ; that they should not display their beauty and ornaments except what must ordinarily appear thereof. “). The prophet interpret what must ordinarily appear to be her hands and face in the hadith reported by ‘Aisya :”Once my niece looked in at our house. At her sight the Prophet turned away. I said:”This is my niece!” The Prophet answered:”If a girl reaches puberty and she has her menses, it is inadmissible for her to reveal any parts of the body except her face and this (then the Prophet grappled his other hand in such a manner that between the grasp and the wrist there was a space of one grasp left)”. See: Al-Qurtubi M. Al-djami’ li ahkyam al-qur’an. Volume 12, p. 152.
2. The material must not be so thin that one can see through it.
3. The clothing must hang loose so that the shape / form of the body is not apparent, consist of bold designs which attract man’s attention . Prophet Muhammad (pbuh) warned that “the women who are dressed and stripped at the same time, who have a slinky gait and thus incite men’s lust will never enter Paradise and will not even breathe in its flavour” ( a hadith from Abu Hurayra narrated by Muslim).
4. The female clothing must not resemble the man’s clothing. Prophet Muhammad (may the Lord greet and bless him) severely censured the women imitating men and the men imitating women, for such behavior is alien to human nature ( a hadith narrated by Ahmad, Abu Daud, at-Tirmizhi and Ibn Madja, from Ibn Abbas)
5. Clothing should not be worn for the sole purpose of gaining reputation or increasing one’s status in society. A hadith agreed upon Bukhari nd Muslim narrated that the prophet said: On the Day of Resurrection, Allah will not look at the person who trails his robe behind him out of pride
Here are some examples of woman cloth considered to be modest in islam that satisfy those 5 conditions