How can I get more defined abs ?!

This is going to sound really funny to you but sit ups and weight training exercises will not give you nice defined abs. it only reaches one part of your abs. Hip Hop is actually THE BEST workout you can do to define all parts of your abs and torso
I would also reccomend Alot of protein and Carb foods so you can bulk up (Eggs, chicken, fish, beef, pasta and meatballs, bread) as well as strenth train using dumbbells, barbells, sit ups ect.
just Dance and eat right and you'll bulk up :P

try doing more ab workouts and push yourself harder !
im a 15 year old girl, 172 cm and weigh 59kg, and i can do 258 sit ups in one set/go.

firstly, try these : ( try do this course once each day)
30 seconds of normal sit ups.
30 seconds of right oblique crunches. ( going towards the right of your body)
30 seconds of left oblique crunches ( going towards the left of your body )
30 seconds of bicycle crunch ( feet in air, and chest up whilst lying on back, crossing over your left elbow to right knee, then right elbow to left knee.)
30 seconds of reverse crunch ( two feet in the air (hook like position) whilst crunching)
30 seconds of long arm crunch ( whole body lying flat on floor, lifting your arms above your head)
30 seconds of crossover crunch ( much like bicycle crunch, except you put your feet on the ground after each cycle)
30 seconds of half curl ( normal sit up postion, arms out in front, touch the knees and then back again )
30 seconds of vertical leg crunch ( legs straight and up in the air, as straight and high as possible, whilst crunching )
and aim to do the plank for a minute.

GOODLUCK ! :)

use weights while doing sit up. Doing 25 sit ups every 2-3 days is good but its not good enough. if you want abs you have to work on them. I do 100 sit ups every single day and its still not enough (for me)

Try doing 50 sit ups every day untill you can get to at least 100 then start using a weight to build your abs even stronger. The weight will help them get that "poped out" look

Junk food is not good for your health. Try eating organic foods rich in protein. Or if you want quick result go to gym and work it out and take some supplements not steroids. By the way, try searching for Monggo it is rich in protein and eat fish such as tuna. Good luck!!

You should keep up your regimen of working out, but you should start eating things with a lot of protein. You need protein to help your muscles build themselves up.

You can find protein in meats, eggs, dairy products, soy, nuts and many other things.

Do 100 sit ups (sets of 25 if you wish) every day and lay off the junk food. There's healthy alternatives for snacks that you should look into

jogging is an excellent exercise because it let you lose weight
evenly throughout your whole body. If you want to lose weight in
specific areas, you should target them with exercises. If they are
your problem areas, they will be very difficult to tone. You will have
to work double on them. The best approach is this:
1. Lower/control your daily calorie intake (control for normal
weight, lower for overweight).
2. Run/jog to lower your overall body fat percentage.
3. Target your problem areas with exercises.
an excellent exercise, you can do it in front of your TV: sit on a
stool, and put your toes under something (piece of heavy furniture,
for example). In your hands hold a little dumbbell. Please, make sure
that it is not very heavy, start with one kilo, for example, or you
will damage your back and spine! Slowly move the upper part of your
body back, until it's parallel with the ground. Stop for a second and
move it back to the sitting position. Repeat ten times. Every week add
to the number of repetitions. You will see the results in a week,
guaranteed! You will see or feel under the fat - if you have any - six
pack and muscles. Dumbbells do wonders. Much better than these
crunches - I came up to three hundreds and there was no results AT
ALL. With the dumbbells you will see it in a week.