Romance is amazing. But what if a relationship begins with romance and after a while, it just ... stops?

In the best relationships, you fit together like a hand in a glove. The familiarity is reassuring. But sometimes comfortable love becomes lazy or even careless, and that can easily undermine a healthy relationship.

Fights brew, disagreements simmer and the spark that pulled you together initially can fade. Bailing out when times get tough is certainly not what you signed up for, and it's far from the unconditional love you've always dreamed of.

People crave romance, acceptance, and, ultimately, unconditional love. But is unconditional love real? And if it is, how can people show their unconditional love to their partners?

What is unconditional love?

In order to understand what unconditional love is, we should first explain the technical definition of unconditional love (though, of course, what it means may vary based upon your family history and unique point of view).

The basic definition of unconditional love is "affection without any limitations, or love without conditions."

With movies and songs romanticizing only the beginning stages of relationships, knowing what love is meant to look like in a long-term relationship gets confusing. Unconditional love seems so far away from that.

But if unconditional love is your goal, you're going to have to learn to grow your love together — to commit to deepening your love so that it will last. Even if it sometimes feels less passionate, unconditional love can carry you both through the natural changes of a relationship that's built to last.

We asked a group of YourTango Experts to help us understand the different meanings of unconditional love in relationships, and here's what they told us.

What unconditional love means in healthy relationships:

1. Unconditional love gives us space for what is needed to grow.

“The trick with unconditional love is to focus on the authenticity of a person; seeing their inner beauty and strength without getting caught up in on what they say or do," says Ellen Nyland, a certified life and business coach.

"If you don’t agree or like what your loved one says or does, you don’t take your ultimate love away and you don’t take it personally. And if you have to let them go, you can let them go in love.”

2. With unconditional love, partners choose who they want to be — and when.

“Unconditional love in the real world involves accepting your partner for the flawed, flesh and blood person they are, not the idealized version you might want them to be," says Lesli Doares, a therapist and couples coach.

It means accepting their feelings, perceptions, experiences, and viewpoints at face value without the need for them to defend or justify them because they are different from yours.

Unconditional love can include making requests for changes in their behavior but being able to graciously adjust if the answer is ‘no’.”

3. Unconditional love means understanding that there's a difference between feelings and reality.

“Unconditional love is being able to witness the anger, the sadness, the shame or guilt that arises in your partner and yet remain focused on the core of who they really are," explains Mandy Agnew Ph.D., therapist, healing guide, spiritual mentor, and the founder of Core Wisdom.

"Gaze upon your partner, see through their personality characteristics and focus upon their divine love within. When we witness the divine in another, we bring that part of us to the forefront, and from this place comes the capacity for unconditional love.”

4. Partners realize the value of staying present in the moment. Feel the connection, then speak.

"First connect, then act. What if we pause for a moment, turn to the present moment, feel the heart and connect with each other for real before we speak or take action?" asks Nicola Amadora, Ph.D., psychologist, mindfulness teacher, and relationship educator.

"Even the most challenging issues can be taken care of if we give precedence to truly meet each other first. It is simple, feels natural, but connecting takes practice. For, when we feel in touch with the pulse of life and each other, love emerges and shows a way, one you may not have seen before.”

5. With unconditional love, both partners understand that there's room for 'we' and 'I'.

“Intimacy is essential to a healthy relationship but clinging not so much. Paradoxically, the joy of being together is enhanced by the necessity of having time apart," says Stephen Dynako, author of "The Self Aware Lover".

"Love in its authenticity understands that each partner is not dependent but interdependent. The need to be constantly connected to one’s partner is more about fear, whether known or unknown than it is about love. Love transcends space, so partners truly in love understand the power of their love regardless of their physical proximity at any moment.”